Are the Strauss criteria for diagnosis of LBBB best to predict outcome of CRT

 Are the Strauss criteria for LBBB diagnosis best suited to predict favorable outcome for CRT ?

Jastrzebsi et al have published data suggesting that the answer to that question is yes. The authors compared four EKG criteria for the diagnosis for LBBB and then compared the outcomes of CRT of patients defined as having LBBB by the various criteria. Patients with Strauss defined LBBB did better than the patients with LBBB defined by other criteria.

This study supports the notion that LBBB defined by Strauss detects so called "true LBBB" with delayed activation of the lateral left ventricular wall and the abnormal inter-ventricular septum motion which can be detected by the "septal flash" on cardiac echo exam. In other words the Strauss EG patterns seems to detect patients whose conduction defect(s) is most likely to be corrected by CRT differentiating it from various  "non-specific intraventricular conduction defects".

Jastrzebski,M et al Comparison of fojr LBBB definitions for predicting morality in patients receiving cardiac resynchronization therapy. Ann Noninvasive Electro 2018 23 (c) e 12563

Smart phone apps for Medtronic pace makers good for patient?or good for company?

 My pace maker battery life is on the downslope  of available electrons.This week I had an in office PM interrogation and the company tech took the opportunity to promote their new option ( for some units) namely an app for a smart phone to replace the bed side transmission unit I have now. 

I personally believe the patient  should  have full access to all of the information typically displayed on the interrogation reports.What Medtronic seems to offer to the smart app holder is the battery voltage reading and the expected battery lifetime and the daily activity.   You will need to use your app to send in the interrogation to the Medtronic mother ship from which your physician or the third partly interrogation report reader company can access the report.

So  now it seems that  gathering the data from your Pace Maker and transmitting  it to Medtronic falls upon the patient and his internet connection and his modem/router. while previously all of that was done by the hardware and software supplied by the pace maker company. You did not need an internet  connection or even a phone line which in the past was a means of sending in data to the company/

My thinking is that the current bed side system works well and I see no reason for me to take on the responsibility of the care and feeding of the electronic mechanisms and hardware to transmit the interrogation.When and if the bed side unit fails or wears out Medtronc will send you another without charge.When your smart phone dies you will replace it .

In 2013 the Heart Rhythm Society published a position  paper on the issue of remote interrogations (RI) and remote monitoring  (RM) of CIEDs ( cardiac implantable electronic devices).  As pointed out in the HRS paper, RI and RM are often used interchangeably with RM being used " colloquially for both" 

   

Libertarian takes on covid vaccination mandates and anti mandate mandates

 Robert A Levy of the Cato Institute discusses some aspects of the recently announced covid 19 mandates on the Septembers 1 Bob Harden Show podcast. 

Interestingly  Levy did not specifically use the term which is   the so called prime directive of libertarianism. The non aggression axiom. If one believes that the world is in the throes  of a pandemic involving a respiratory virus that spreads by aerosol transmission and that this  disease is very contagious and that vaccinated and of course unvaccinated can spread the disease and that masks mitigate the risk and that vaccination mitigate the risk then not wearing a mask in public in an area in which the disease is spreading should be considered an aggressive act.Therefore not wearing a mask under those conditions is about as un libertarian a thing as there be.  

 Governors Abbott and DeSantis have through their executive actions and/or legislation they sponsored acted to limit the private property rights of business owners in their states. Business owners have the right to set the terms and conditions of their employees and the terms of business arrangements of their customers. Both governors have prohibited  businesses from utilizing a de facto vaccine mandate regarding their customers. Conservatives have long favored a " no shirt,no shoes no service" business approach. which they now discard in an effort to what they seemingly believe to   gain approval of  a minority of Republicans who are perceived to be strongly anti  mask and anti covid vaccination under the faux banner of preserving freedom while actually abrogating the property rights of business owners. 

My "journey " with a pacemaker and His Bundle Pacing

 In October  2015 I was implanted with a pace maker which used a His Bundle (HB) lead.Every thing it seems now is thought of or written about as a journey so I tell my journey.

Since I developed a high grade second degree heart bock that was precipitated by exercise and a left bundle branch block (LBBB) also,I was a candidate for a pacemaker (PM) and cardiac resynchronization therapy  (CRT) which at the time was synonymous with bi-ventricular pacing (BI-V) .

BiV has been  accomplished by atrial pacing,right ventricular pacing and left ventricular pacing which was done by inserting a pacing lead into a vein of the epicardial surface of the left ventricule (LV) .which was accessed by placing a catheter into the coronary sinus in the right atrium and threading it into a LV epicardial vein.

My EP cardiologist had a different approach. He implanted a lead in the right atrium and placed the ventricular lead near the bundle of  His in the interventricular septumThe third  lead was placed in  a vein on the surface on the left ventricle.This bi-V approach  is done in cases of heart failure (HF) in which there is significant desynchrony of the left ventricle (LV) which reduces cardiac output and leading to significant deleterious cardiac remodeling. 

The LV lead was to be a back up lead and  in the first five years was not needed as during implantation the Right ventricular catheter recorded a His Bundle signal  which captured the Purkinje System and provided a narrow QRS complex replacing the LBBB. The HB pacing was considered to be "non-select" HB pacing as both the His Bundle and a portion of myocardium was stimulated giving an EKG with a delta wave resembling the EKG of an anteroseptal preexcitation pattern.

Non select HBP is thought to be as effective as select HBP ( in which there is only capture of the His Bundle and the EKG has an isoelectric  interval between the stimulus and ventricular capture signal) in terms of cardiac output.

HBP typically has requested a higher capture voltage than does right ventricular apical capture and has a greater incidence of need for lead replacement and may have a lower r wave. HBP has also required a longer implantation time and higher incidence of  failure to capture rate. All of those issues have become much less of an issue as operator experience has increased and better catheters have become available with procedure times being shortened, capture threshold lower, and fewer cases of that require a  lead replacement. 

The post implantation period was not without drama. The first night the chest pain was severe and frightening and I felt lightheaded. I had been NPO from midnight of the day preceding the procedure day  and although the procedure was scheduled for 7 am , because of an intervening emergency it was after one pm before I went into the cath lab by which time I was likely moderately volume depleted. 

This lead to a situation in which I had chest  pain and a low blood pressure.My wife also a physician were able to convince, badger and intimidate the rookie nurse to run in more fluid.The fluid and a shot of morphine  relieved the pain and volume depletion  correction alleviated the weakness. 

 3 days later I developed left sided pleuritic chest pain,a heart rate of 150 (shown to be atrial flutter on EKG) and an emergency Pulmonary CT angio was interpreted as showing several pulmonary emboli in the left lung and a peripheral pulmonary infiltrate in the same area. 

 Symptomatic Pulmonary emboli after pacemaker implantation are uncommon.One  study using  V/Q lung scans demonstrated probable emboli in 15% of a small number of asymptomatic casesI had a repeat pulmonary CT scan following 3 months of apixaban which was normal .

Six years later my pacemaker battery was nearly end of service and I had a pacemaker replacement. No post op complications occurred this time.

 

 In 2006 ,Rafael Barba-Pichardo et al  from Spain published a series of cases of HBP which included a single case of using the His Bundle to pace a patient with heart failure in whom a LV vein could be assessed. This appears to be first case report of HB paced CRT/

In 2010  DL Lustgarten et al accomplished direct His pacing in 10 patients who were candidates for Biv pacing.  ( Lustgarten Dl Electrical resynchronization induced by direct his bundle pacing ..Heart Rhythm 7 , 2010 p 15 

In 2017 Rodney Tung from Chicago and Kalyanam Shivkumar from UCLAA (2) reported a series of 21 patients in a study the purpose of which to assess the feasibility of a His-bundle lead for CRT in place of the coronary sinus lead.

1)Barba-Pichardo, R et al , Permanent His Bundle Pacing in patients with infra-Hisian atrioventricular block. Revista Espanola de cardiologia, vol 59m553-558

2)Ajijola,OA et al Permanent HIs-Bundle pacing for cardiac resynchronization :initial feasibility study in lieu of left ventricular lead.Heart Rhythm2017,sept 14 (9) 1353-1361

Exercise level ,cardiovascular risk reduction and risk of atrial fibrillation

 Six years ago  after I had recovered from my pacemaker implantation and the subsequent complications  (pulmonary emboli and pocket hematoma)  I mentioned to my EP cardiologist that I believed that I could run a half marathon. I had abandoned thoughts of completing a full marathon  because for  the proceeding two years I had barely finished in under six hour which was the cut off time to be officially counted as a finisher. for the full marathon.

The EP doc said that is not a good idea and when asked why he mentioned the risk of atrial fibrillation. I thought he was wrong but let the mater drop. I did not doubt that there is a relationship between running and AF but felt sure that the level of exercise sufficient to train for a half marathon was not in the range where there would be worry about AF.

The irony of recently seeing the EP doc's picture posted by him on a social medium site showing him with the half marathon medal along with his finishing time  did not go unnoticed. 

This is a good time to review the current recommendation for exercise to reduce cardiovascular risk,at what level of exercise  does it becomes too much or a good thing,and at what level does there appear to be an increased risk of atrial fibrillation. 

Currently the widely accepted view  and the WHO recommendation is that as a minimum one should exercise at a  level of 8 met hours per week.This is equivalent to 1/2 hr of moderate exercise for five days a week. Moderate is defined at a 3-6 Met level.8 met hours per week can also be achieved by vigorous exercise ( defined at greater then 7 mets) for 1.25 hours per day for five days  per week.

8 met hours per week is good but it is widely believed that at least a bit more is better, for example exercise at twice the minimum level would be better in term of cardiovascular risk reduction.This would be exercising at a moderate intensity for one hour a day for five days a week. 

So it seems in terms of cardiovascular risk reduction more is better but there must be limits to that.Is there a level of exercise beyond which there is no further improvement in risk reduction?

Eisvogel's data analysis suggest that that level is around 41 met hours per week. That is five times the minimum or 2.5 hours of moderate exercise per day five times a week . Interestingly the risk reduction exercise volume curve flattens out at a much lower level for vigorous  exercise, at 11 Met hrs per week according to Eisjvogels analysis data from Wen and from Aren.    

At what level of exercise can we expect an increased risk of atrial fibrillation?

Data from Ricci 2018 suggests that level may be about 55 met hours per week or 7 times the minimum recommended dose which would be 3.5 hr moderate exercise per day five times a week 

The level of exercise sufficient to train for a half marathon is definitely less than the estimated threshold for increased risk of atrial fibrillation. Check out any of the numerous half marathon training program and you will see the volume suggested is much less than 7 times the minimal WHO recommended exercise level.

 

Automatic threshold capture proven to work well for apical pacing but not for His pacing

 The thresholds for capture of the ventricular muscle may change over time with changes in the myocardial excitability which may be related to disease progression , electrolyte variation ,exercise,temperaturre etc. 

With the development and proven effectiveness and safety of automatic threshold determinations pacemakers were able to have longer battery lives and  there was more assurance of ventricular capture than was possible with in office threshold determination every 3 or six months as was the practice.  Automatic capture management (ACM) s have clearly been a useful development in PM technology.Patients' threshold levels could be measured daily. 

Various pacemaker manufacturers have developed their own automatic capture management systems and have become commonplace..

However since the increasing use of conduction system pacing in the form of His Bundle pacing,problems have become evident with  ACM algorithms.

Journal articles by Haran Burri and P. Vijayaraman have described the problems with HBP and ACMs. In regards to ACM issue details vary with what port on the PM is the His lead attached and whether there is selective or non-selective His pacing.

The story of left bundle branch block from interesting anomaly to a electrophysiologic fixable condition

In the beginning the EKG pattern of LBBB was an interesting phenomenon . William Einthoven in 1925 presented a case with a tracing that had also been recorded 31 earlier in the same patient. No one knew what the tracing signified and Dr. Einthoven remarked that the patient with this finding seemed to not be bothered by any heart symptoms.

As time went on it was realized that the pattern represented a "block" or conduction delay in the left branch of the Bundle of His and became established as a reliable sign of heart disease, it being often associated with ischemic heart disease,hypertensive heart disease and various cardiomyopathies.

Occasionally LBBB was noted in patients without obvious structural heart disease and the effect(s) of the cases of "lone "LBBB  on cardiac function was not initially appreciated.

 However, as early as  1979  physiologic studies  (1) on "lone LBBB" demonstrated significant septal and left ventricular  wall motion abnormalites associated with decreased left ventricular function and impaired relaxation. Later numerous studies on LBBB have detailed  the pathophysiology of the electrical and mechanical dyssynchrony of LBBB as well as molecular perturbations and deleterious ventricular remodeling.

In 2005 and 2013 reports from France described a cardiomyopathy that occurred with variable latency periods from the onset of LBBB that was to varying degrees reversible by cardiac resynchronization therapy (CRT) . Think about that for minute. LBBB may cause a cardiomyopathy that is possibly reversible by CRT.

Recognition of the role of a prolonged QRS and decreased cardiac function and the role of ventricular dyssynchrony in HF lead to idea of cardiac resynchronization therapy (CRT) in which there was pacing of  both the right ventricle and the left ventricle( with a pacing lead in  a coronary vein accessed via the coronary sinus)  in an effort to restore synchrony between the septum and the ventricular free wall.

From 2001 through 2009 there were several randomized clinical trials that demonstrated the efficacy of CRT in improving cardiac function, lessening  symptoms and in reducing mortality in heart failure patients.

As CRT was increasingly used to treat refractory heart failure (HR) it was realized that patients with a LBBB pattern were more likely to respond favorably and that CRT was essentially a treatment for LBBB.

Risum has published data from speckle tracking echo studies that suggest that the LBBB patients with HF who  respond favorably to CRT are those with a particular contraction pattern consisting of early septal activation and bulging of the lateral left ventricle followed by contracting of the LV with peak contraction occurring after aortic valve closure.

Will morphing physicians into health care providers destroy their placebo-witch doctor power

Thoughts catalyzed by lecture by Dr. Olshansky on the placebo effect  at Methodist Cardiology Rounds.

In out ancestral, tribal- based behavior maybe there is some DNA driving us to seek out and follow leaders, strong wise individuals who can shepherd us through tough times- societal and even personal as in health care matters.

Knowing as much as I know about doctors and medicine and clinical trials and  fragile and contradictory  guidelines  and the utter impossibility of being able to keep up with every thing even in  your own  subspeciality  and the temporal fragility of medical advice I think I have largely lost the capability to benefit from the placebo- witch doctor -effect when -I absolutely have to see a doctor HCP.

The question I am raising here is will HCPs without MD degrees pack the same placebo power as physicians for those who are not as skeptical as I am of the physician's ability.

Does what goes on behind the anesthesiologist drapes stay behind the drapes?

 At least some of what occurs behind the anesthesiologist drapes stays there not  being completely captured by the surgeons op note.  This is the case because the surgeon does not know what goes on in real time focused as he should be on the details of the procedure.

The story

I have a pacemaker, a dual chamber  in DDD mode with the right ventricular lead placed in close proximity to the Bundle of His.Typically this is referred to as non select His Bundle pacing, I was to have surgical procedure with the operative field to be within a few centimeters of the pacemaker .

It is common practice to deactivate the sensing function of the PM since the cautery typically used in surgery can emit electromagnetic energy  ( electromagnetic interference (EMI )) that can damage the PM or change its function with variable clinical consequences.

The sensing function of the PM can be disabled by the application of a magnet over the PM.This converts a  PM in DDD mode to one in D00 mode in which the atrium and ventricle are paced typically at a rate of 85. This is called asynchronous pacing and referred to as magnet mode .

This eliminates the risk of EMI but at the cost of limiting the heart ability to increase cardiac output and poses the risk of ventricular tachycardia or ventricular fibrillation if a pacing spike should occur at the vulnerable phase of repolarization. If the patient has a functioning sinus node and  intact electrical transmission  there will be two competing rhythms .  

The operative record include a series of Blood pressure recordings all of which in my case were normal.Yet the medication record includes levophed which would have only been used if the blood pressure has decreased significantly. So that fact must have stayed behind the drapes.

Could the presumed blood pressure drop be due to the magnet mode not allowing an intrinsic increase in cardiac output assuming there was a valid reason for the use of levophed?

 

Can we define the level of high volume endurance exercise above which mortality risk increases?

Can the level   of high volume endurance exercise above which mortality risk increases be defined.

An important study with data from the Cooper Clinic in Dallas provides some information on that question.

Defina  et al (1) presented data from a large cohort of men ( 21,758) with ten years of more of followup. In the group there were 432 men with  an  exercise history of equal to or greater than 3000 met-min per week .This is approximately equivalent to one hour of vigorous activity per day ( at a level greater than 7 Mets  which is the oxygen uptake required to finish Stage 2 on the Bruce protocol).This is a level of exercise about 6 times the minimal level of vigorous  ( greater than 7 Mets) exercise per week recommended by the 2018 guidelines.

Men in this group had a greater risk of having a coronary calcium score of 100 or greater but their risk for cardiovascular mortality (CVD) and all cause mortality was not greater than men exercising at lower levels and was lower than the least active men  in that cohort. This was the case even though they had higher CAC scores which generally predicts a higher cardiovascular risk.

Franklin and co-authors (2) said this about the DeFina study:

" These finding refute the notion that high-volume endurance activity ( greater than one hour/day) increases mortality regardless of CAC level"

The issue in the De Fina article  was the signficance of increased CAC in long time endurance exercisers on cardiovascular mortality but it also  provides some information regarding the title question .

1)DeFina,LF et al Association of all-cause and cardiovascular mortality with high levels of physical activity and concurrent artery calcification. JAMA Cardiology 2019 42 (2) 174

2)Franklin, BA Exercise related acute cardiovascular events and potentially deleterious adaptations
following long term exercise training. Placing the risks into perspective-An update A scientific statement from the American Heart Association. Circ 2020 Feb 26 PMID 32100573

EKG alternating between LBBB and non specific intraventricular conduction defect-Mechanism?

 A 75 year old man sought medical attention from his internist because of a several week period of decreased exercise tolerance.EkGshowed sinus tachycardia,left axis deviation and a left bundle branch block (LBBB) that fulfilled the Strauss criteria for LBBB diagnosis.

Two days later the patient was seen by a cardiologist and an EKG done that day showed a non specific intraventricular conduction defect with right axis and clearly did not meet the criteria for LBBB. In the interim between the two EKGS there was no change in the patient's clinical status. 

Two weeks later EKGs done as part of an echo exercise stress tests again showed classic EKG with Straus criteria.

What could explain the changes in EKG pattern? 

A change from left axis deviation to right axis could be due to a pulmonary embolus but there were no new pulmonary symptoms and no history of physical findings of DVT.

Is there a big voltage drop( pun intended) between skillful Pacemaker implantation and the follow up?

 Current training for an Ep cardiologist following four years of medical school consists of three years of internal medicine residency,three years of a general cardiology fellowship and a two year fellowship in EP cardiology, a total of 12 years after obtaining a college degree..

A board certified EP cardiologist is without doubt a very well trained physician. Someone who is  evaluated  by a board certified EP and receives the implantation of a pacemaker has very likely received some high voltage, high quality medical care.  At least some of time after that it maybe all downhill. Why would that be?

Often the post care and the periodic evaluation of pacemaker function is done by medical personnel much less  trained and knowledgably than the EP. Sometimes the voltage or medical quality drop is striking.For example, My EP can , in theory any way, accessed by a patient portal. The Patient portal is presumably monitored by , in this case. an "assistant to the physician" according to her name badge. So my  questions about my PM are reviewed by an AP ( note this is not a PA, which is a trained,licensed mid level health care provider. ) I do not know what training if any an AP has.

Voltage drop refers to a decrease in voltage as current flows through an electrical circuit. Points in a circuit with increased resistance are points of voltage drop.

The hematology literature seems unaware of the effect of strenuous exercise on blood iron related measurements

 In their authoritative review in the Journal Blood (1) in January 2019 Drs. Weiss,Ganz and Goodnough discussed what is known about iron deficiency anemia (IDA) and anemia of inflammation (AI) and devoted a section as to how to differentiate between the two and to recognize patients in whom both conditions exist. 

What was not discussed or even mentioned was exercise as a cause of iron deficiency anemia.Neither was  mention made of the effect of a session of aerobic exercise on various iron status blood tests.Much has been written about exercise and iron deficiency and IDA and the role of exercise induced hemolysis and its contribution to an increased iron requirement in endurance athletes in the physiology and sports medicine literature .

1) Weiss, G, Ganz,T and Goodnough,L Anemia of Inflammation. Blood 2019 133 (1) 40-60

Can aerobic exercise reverse loss of compliance in early (Stage B) HFpEF

 Can aerobic exercise reverse loss of left ventricular compliance in  early (Stage B ) heart failure with preserved ejection fraction (HFpEF)? Stage B HF is asymptomatic with increased in either natriuretic hormone or troponin with structural changes, i.e increased wall thickness indicating Left ventricular hypertrophy (LVH).Stage B heart failure is defined by ACC/AHA guidelines as having structural heart disease but no current or prior symptoms of HF.

  Do we have another possibly ground breaking research paper from Dr. Ben Levine from the Institute for Exercise and Environmental Medicine In Dallas . In earlier publications Levine has demonstrated that long time endurance exercise can preserve at least to some  important degree left ventricular compliance. 

It is well established that normal sedentary aging leads increased stiffness of the left ventricle and Levine has shown that this stiffness can be mitigated by long time endurance exercise and that LV compliance can be improved  by an exercise program instituted even in early middle age.However by late middle age ( i.e past age 65) it is too late to reverse the stiffness. 

In patients with LV hypertrophy and elevated cardiac markers Levine was able to show that one year of committed exercise training ( which included some high intensity interval training) was able to increase 02 Max and decrease left ventricular stiffness.

1)Hieda,M et al One-year committed exercise training  reverses abnormal left ventricular myocardial stiffness in patients with Stage B heart failure with preserved ejection fraction.Circulation 2021;144, 934 -946 September 21 2021 full text is available

So how does cardiac conduction system really work?

 Using recording catheters in the left ventricle, Upadhyway et al (Circulation 2019) demonstrated that the location of the blockage or slowing of the electricity  in patients with surface EKG findings of LBBB was not predictable from the morphology of the surface EKG pattern of left bundle branch block (LBBB). This was the case regardless which criteria for the EKG diagnosis of LBBB was used, i.e. either the Strauss criteria or those recommended by the ACC/AHA/HRS criteria. In some cases there was no detectable blockage in the Purkinje system and therefore in those cases conduction system pacing would not correct the abnormal EKG pattern nor any associated  cardiac functional impairment in those patients. 

Dr. R Mahmud and S, Jamal studied the effect of nonselective His Bundle Pacing ( NS HBP) in 41 patients with LBBB. In 23 of those NS HBP decreased the prolonged PLWAT ( peak lateral wall activation time) normalized the QRS axis and increased Lead I voltage and normalized the Left axis deviation and resolved the mid ORS notch.  

The theory of longitudinal dissociation has become the standard explanation for how pacing in the His bundle could correct the conduction defect thought to exist in patients with the EKG pattern of LBBB.If the blockage was actually anatomically  present in the left bundle  how could pacing in the Bundle of  His  which is proximal to the  blockage in Left Bundle normalize the EKG. The secret is said to be that the fibers that are predestined to be those in the Left Bundle are already anatomically distinct within the His bundle and a lesion or a something that slows electrons  a happen in the His and the electrode is placed distal to that problem site and viola the impulse travels down The distal HIS and to the Left bundle .

It is now thought that the majority of LBBB cases are due to blockage or slowing of electricity in the His Bundle 

Mahmud has also demonstrated that NS HBNP can correct  the pattern of RBBB by " activating early the delayed right ventricular free wall depolarization." NS HBP produces a fusion beat with the fusion of the activation  early anterior septal wall with varying degree of His Bundle activation.

Is the COVID Pandemic legacy simply more of the same.

 Is the COVID pandemic legacy going to be more of the same?

The is the picture painted by Ed Yong writing in The Atlantic  Sept 30,2022

Quoting from Yong's essay-Covid is on track to kill about 100,000 American a year with 50,000 new infections  daily .US accounts for 16% of global Covid cases having only 4% of the world's population.The country that helped create vaccines in record time is 67th in the world in vaccinations,

The public health infra-structure  was not sufficiently strong to do battle with covid and now, if anything, it may be weaker at least to the degree that significant  numbers of Public health workers  ( physicians and others) have left the field in part because of the vitriolic attacks  by the most radical of the anti vaccination activists.  

I have read that at least part of Hayek's defense of free markets was pragmatic- it worked better, much better in some regards than central planning. But are there circumstance in which free markets do not perform well at all. Is health care delivery one of those exceptions?

 Is the US hybrid health care mixture of private enterprise and government spending and government controls  plus increasing control of medical practice by non physicians ( let alone  venture capital getting its paws in the medical tent) incapable of  getting the job done. Prior to Covid I would have thought that our current system (or current situation) would handle things well. But it did not. 

Two things in the last several years have shaken the priors I had regarding the value of free markets and the harmful effect of governmental control. 1) the Covid pandemic  2) A 10 month journey into the other side of  medicine as practiced in a large "not for profit" hospital system  with  its bureaucratic  delays  and its tendency to damage the doctor patient relationship and the outrageous charges . The corporate practice doctrine has been virtually destroyed and at least 70 % of the physicians in the country are in effect salaried employees even though the mumbo jumbo of their contracts with the hospital and other entities would pretend that is not the case.

Exercise,hepcidin,glycogen depletion and iron deficiency

 Hepcidin has been described as the master regulator of iron. Hepcidin impedes GI tract absorption of iron and decreases movement of iron from the macrophages to the bone marrow.In the anemia of inflammation (AI),hepcidin is chronically elevated so that iron absorption and the transfer of iron from macrophages to the bone marrow is significantly decreased. The anemia is in a sense self limited because at some lowered level of hemoglobin the erythropoietic drive is able to counteract the effect of hepcidin so that the hemoglobin does not continue to fall perhaps through the effect of erythroferrone produced by red blood cell precursors. Hepcidin does not play a key role in the typical case of a runner with iron deficiency anemia (IDA) as long as there is no chronic glycogen depletion,So what does glycogen depletion have to do with this?

Strenuous exercise acutely increases the hepcidin level but after several days of exercising at the same level or slightly higher level the hepcidin return to the baseline value. Running,as a prototype of a repetitive  strenuous exercise is associated with iron deficiency and iron deficiency anemia due to loss of iron from the GI tract,sweat and urine and from repeated bout mild,self limited hemolysis combined with an inadequate dietary iron intake.

However, there  at least running scenario in which elevated hepcidin may contribute to  Iron deficiency and even iron deficiency anemia. Repetitive strenuous exercise in a person who is in a significant negative calories balance with glycogen deficiency can result in chronic elevation of hepcidin and decreased iron  absorption .

Dr Aya Ishibashi et al (1) demonstrated in several long distance runners that serum hepcidin level were elevated on day 4  following three days of strenuous exercise done under conditions of limited calorie intake which correlated with reduced muscle glycogen levels. 

The cytokine, IL 6 is known to stimulate release of hepcidin. Keller et al (2) demonstrated that working skeletal muscle activated transcription of IL6 which they said was "dramatically enhanced "with glycogen levels are low. 

A study utilizing exercise regimens  to simulate military exercises (3) also demonstrated that negative energy balance and glycogen depletion was associated with persistent elevation of hepcidin levels.Another military exercise study (4) demonstrate elevated IL  6 and hepcidin at end of a 7 day high energy output military exercise.Glycogen was not measured but most likely the participants were in a negative calorie balance.

1) Ishibashi, A et al Effect of low energy availability during three consecutive  days of endurance training on iron metabolism in male long distance runners. Physiological report vol 8, no 12 e14494 June 2020 

2)Keller, C Transcriptional activation of the IL-6 gene in human contracting muscle: influence of muscle glycogen content. FASEB J 2001 Dec 15 (14) 2748 E pub 201 Oct 29

3)Hennigar,SR et al Energy deficit increases hepcidin and exacerbates decline in dietary iron absorption. J of Clinical Nutrition 113, Feb 2021

4) McClung,JP et al Effects of a 7 day military training exercise on inflammatory markers,serum hepcidin and iron status Nutrition J. 2013 Nov 4  12 (1)

Another cause of medical care voltage drop-medical assistants

 Different commentators have used the term "voltage drop" to refer to various things related to medical care. One use is to refer to the efficacy-effectiveness gap, i.e the difference in outcomes from clinical trials to treatment in the real world in which subjects are not carefully selected and care is not closely monitored to conform with the clinical trial protocol.

Here I use the term to refer to the drop off in communicative content  and efficiency and content validation when a medical assistant is the interface between the patient and the physician. The following is based on a real scenario .

On day zero a patient met with a gastroenterologist with a clinical picture which warranted a colonoscopy and an upper GI tract endoscopy ( which in current jargon is called a bidirectional endoscopy ) Because the patient had a pacemaker (PM) the patient was informed that his EP cardiologist would have to give clearance . before the procedure could be scheduled Eight days later the  GI docs (MA)sent a message to the EP doc office whose MA   apparently did not reply until day 13 . The patient then was informed that for some undisclosed reason the clearance  was unsatisfactory and it was not until day 20 that a second clearance was sent to GI and then the procedure was scheduled for 2 weeks later.

It should be noted that the two physicians both work for clinical practice groups which are part of the same large "not for profit hospital" system and are actually located on adjacent floors of the same building.

So why did it take three weeks to obtain a routine pre endoscopy cardiac clearance. Why do I point blame at the MAs rather than the administrative burden that grew up in a large medical system. Obviously both are at fault but I submit the MAs replacing RNS in physician offices to  save money (big salary difference) is replacing someone with very little medical knowledge and maybe  even less sense of responsibility to the patients.

 

The physician physical examination-is it almost extinct?

 The physical examination (PE) was for many years a routine fixture of a person's annual checkup. It seem it is much less so now.

Three of my physician friends who recently retired went in search of a new primary care physician because their PCP also retired.All three found someone but all were somewhat nonplussed when their initial encounter with their new PCP did not involve a physical exam. They were each weighed, and their blood  pressure checked by a physician assistant. One also took part in some elements of the Medicare Annual Wellness Visit (AWV) though he did not know what a AWV was. He was somewhat proud of his artistic skill in drawing a clock face depicting the time ten fifteen .All three admitted they "needed" a PCP mainly to order lab tests and write prescriptions. All of these recently retired physicians were internists and spent a total of 170 years practicing and doing physical exams, so an annual or initial physician visit without a physical exam was hard for them to get their heads around it.In each instance the new physician was a board-certified internist. So what things might account for a sea change in the way internists do business.

Dr. Abraham Verghese is ID internist at Standford and is erudite,articulate advocate of the physical exam and his U tube performances are a joy to watch.Verghese characterizes the PE as an important ritual of considerable value to both the patient and the physician.He emphasizes that the PE is a ritual and rituals have been of great value to humans for many hundreds of years. I am afraid that Dr. Veghese efforts as admirable as they are will have little to no effect because the payment arrangement that internists now face leave little time for physical exams.

Focused physical exams will continue to be done  by ER docs and surgeons and neurologists.

Verghese shows two slides one of the  "old time" ward rounds in which the students and the professor were around the patient and another slide with a group of physicians sitting around a table each with a laptop making " I rounds" . Verghese claims ownership of the term:" I patient". which is the depiction of a patient on the electronic health record (EHR) who only has fleeting resemblance to the actual patient.

In the world of the I patient as he exists in the Electronic health record  the patient often has had a complete physical exam multiple times and a through system review .However,the real life patient remembers no such exams as they were never done but just copied and pasted into the chart  from an idealized template.If a physician signs off on a physical exam that was not done, it that considered fraud.Does that act not pose a risk in any subsequent litigation? Why do physicians practicing in hospitals or large clinic settings allow the phantom exams to be part of the permanent medical record?

Does Cha2ds2 Vasc really estimate risk of stroke due to Atrial fibrillation

 Does Cha2ds2 Vasc (CDVS) score really estimate the risk of a patient with atrial fibrillation (AF)? Or does it estimate the risk of a stroke in a person with vascular disease? I think the latter is the case.

The CDVS tallies up the number of vascular disease points and adds in age and gender and basically provides a risk of stroke based on a estimate of the amount of vascular disease the patient has. The presence of AF is not factored in to the CDVX score. The presence of AF merely provides an opportunity for the health care provider (HCP) to use that risk tool. The HCP give the patient the value from the CHVS algorithm which represent the risk associated with how much vascular disease that the questionnaire reveals . that risk expressed as percent risk of stroke per year . The actual risk of the AF patient would be believed to be increased by the extent to which it is believed that AF is itself a mechanistic cause of stroke, a  widely accepted view that has recently been challenged. S

So is it the assumption that the AF patient for whom a CDVS is obtained has at least that risk of stroke and the presence of AF surely must increase that risk by some factor so that anticoagulation is appropriate. 

"...experience fallacious,judgement difficult" especially in regard to observational trials

 There are four reasons besides causality for an association:

1)chance aka random variation

2 Bias aka systematic variation

3)confounding

4)Fraud (typically not even mentioned in statistics books)

One of the 3 most important insights I have read  in anything related to medicine came  from comments made by Dr. John C Bailard iii in the book he coauthored, "Medical Uses of Statistics"The insight was the recognition of the fragility of medical research in part due to the fact that  statistical measures of uncertainty ( i.e p values and confidence limits) particularly in observational studies reflect only part of the  " uncertainty that can be attributed to random variability"  Medical studies- both randomized trials and observational data- involve  "drawing inference from information that inevitably subject to error " that is not controlled with p values and confidence intervals

In one  chapter he discussed two articles that appeared  back to back in the New England Journal of Medicine in 1983.They were two observational studies dealing with the issue of the cardiovascular effects of hormone replacement therapy in post menopausal women. One study found that the incidence of a type of heart disease was twice as common in the hormone treated group versus the control. The other study found that the hormone treated group have half of the incidence of the control group. 

Bailar wrote an editorial in the same issue in which he explained that he had carefully  reviewed both papers and could find no flaws in the design or analysis of the data.He admitted he did know why the results were so different. 

Life is short, the art long ,experience fallacious and judgement difficult.

Runner's anemia well known to runners and sports medicine doctors, less so with internists

 Having spent many years running far  beyond a reasonable amount to attempt to improve health my blood count profile was that of a typical endurance athlete namely hematocrit and hemoglobin (H and H) at lower range of normal and a larger than average red blood cell size (measured as MCV).

What was going on was that I was running enough ( above some threshold value for a duration- intensity product) to have repeated exercise related episodes of intravascular hemolysis (break down of red blood cells (RBCs) in the blood stream.

Repeated hemolytic episodes cause increased RBC production to account for the loss of RBCs.Active endurance athletes have measurede RBC life span of around 74 days versus  115-120 in a more sedentary person. More production requires more iron for hemoglobin manufacture,

Normally the 1-2 milligram of iron loss daily ( largely through the GI tract as the short lived,iron absorbing duodenal lining cell slough off into the bowels) is easily replaced by iron absorption in some one  with a normal western diet. 

So that with adequate iron intake repeated episodes of hemolysis do not result in anemia.But perhaps not so in a person with meatless diet and even more so in a woman with poor diet who has the added menstrual related iron loss.

 High school cross country coaches and runners are well aware of iron deficiency as a cause of poor performance and sports medicine doctors measure serum ferritin levels as a measure of iron status in their evaluation of an endurance athlete . The  lay publication Runner's World has had well researched articles on runner's anemia for years yet in my experience general internists and even gastroenterologists seem unaware of the entity and somewhat shockingly even some hematologists. (note I have a very small sample size on which to base the preceding claim).

Replace RNs with Medical Assistants -what could go wrong?

 Recent data from Houston Texas indicate that RN's at a large local hospital system earn $ 73  per hour while medical assistants earn  $ 19 per hour.Note we are not talking about Physician Assistants who typically graduate from a 2 or 3 year Master's degree program  and after passing the PANCE exam are licensed to practice under the supervision of a physician with the level of supervision varying between states and the type of medical  practice.

 I recently saw an ad for a local community college showing a young woman with the tittle of Medical assistant" on the ID badge with a caption saying" Last year I was waiting tables ". 

The Medical Assistants  level of education versus the RNs that they have replaced in many settings is not  even close and what ever brief training they may receive  at work or at a community college course is  not likely to instill in them the sense of professionalism that RNs possess nor the savvy that years of experience bring into play. 

 In my recent experience with a large non for profit hospital system Medical assistants had taken over many of the duties formerly done by RNs answering phones, putting patients in exam rooms (wherein exams are rarely done) and making appointments.

Of all the disturbing developments in medicine the worse has to be the entry of venture capital

 One of the greatest fears that the elderly and the near elderly have is to be alone in a nursing home.There is one thing worse and that is  to be alone in a nursing home owned by a venture capital company.

This article  (1) that  documents what happened when a nursing home run by the Little Sisters of the Poor was purchased  a venture capital company makes it clear that you do not want to be a resident in a venture capital nursing home. 

1) "When Privae Equity takes over a nursing home.Yasmin Rafiel, in the New Yoker ./www.newyorker.com/news/dispatch/when-private-equity-takes-over-a-nursing-home

ARBs versus ACEi and the winner is ...

 The amount of analysis done on the comparison of the safety and efficacy or ARBs versus ACE inhibitors for treatment of hypertension is impressive and was recently  comprehensively reviewed  in this article (Why Are We Still Prescribing ACE Inhibitors? (medscape.com) in Circulation.ARBs are the clear winners . Over  30 years ago I decided to prescribe ARBs for myself and patients rather than ACE inhibitors and am pleased to see validation for that decision made on the basis of much less evidence than is now available.