Atrial Natriuretic Peptide and Cyclic Guanosine Monophosphate Response Cardioversion of Atrial Flutter or nbrillation

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Sakti Mookherjee et al* reported on elevated atria1 natriuretic peptide (ANP) levels in patients with atria1 flutter and fibrillation regardless of the presenceor absence of congestive heart failure. After cardioversion, ANP levels decreased in all patients independent of cardioversion mode. In the same setting we measured ANP and its second messengercyclic guanosine monophosphate (cGMP) in 12 patients before cardioversion, as well as 15, 30, 45 and 60 minutes after cardioversion. In a control group we assessedthe influence of the anesthetic agent propofol on the ANP/cGMP system in 6 patients without rhythm disturbance or heart disease.We found no changes in ANP or cGMP during propofol anesthesia. ANP correlated statistically significantly (p >0.05) with cGMP in both groups (r = 0.88 in the control group and r = 0.76 in the cardioversion group). Patients with atria1 flutter or fibrillation had markedly elevated plasma levels of both ANP and cGMP compared with control patients. After successful direct current cardioversion, ANP and cGMP levels decreasedsignificantly in all but 1 patient within 15 and 30 minutes, respectively. One patient with severe myocarditis had slight increases in ANP and cGMP despite conversion to sinus rhythm and decreasein heart rate. We assume that successful cardioversion in patients with severe structural heart disease does not necessarily influence the ANP/cGMP system becauseof a possible compensatory mechanism of ANP to cardiac dysfunction.2 In addition, we found a cGMP release of 150 f 18/mol ANP in patients of the control group; in the cardioversion group the cGMP release was only 109 f 54/mol ANP indicating a minor responseof target cells to ANP stimulation (receptor down regulation). Finally, we conclude that ANP correlates well with cGMP, which is much

easier to measure lacking wellknown preanalytic and analytic problems of ANP measurement.3 Moreover, restoration of sinus rhythm does not always result in a decrease in ANP and cGMP. Peterh!ChkhfW9MD Norbert Genus-,MD Gottfried MierschHfthaler, MD Bernd hhdd, MD Franz Diemtl, MD

Innsbruck, Austria 28 May 1991 1. Mookherjee S, Anderson G, Smulyan H, Suman-Vardan. Plasma atrial natriuretic peptide response to cardioversion of atrial flutter and fibrillation and role of associated heart failure. Am J Curdiol 1991;61:371-380.

2. Weil J, Bidlingmaier F, Dohlemann C, Kuhnle U, Strom T, Lang RE. Comparison of plasma atrial natriuretic peptide levels in healthy children from birth to adolescence and in children with cardiac diseases. Pediatr Res 1986;20: l3281331. 3. Wencker M, Hauptlorenz S, Mall W, Puschendorf B. Influence of blood pressure, heart rate, age, and sex on concentrations of atrial natriuretic factor and cyclic guanosine monophosphate in I24 volunteers. C/in Chem 1989;35:1519-1523.

“Anything to be done right has got to be done by people that make their living at it”

The editor’s editorial with the above title (Am J Curdiol 1991; 67:445-446) makes interesting (and amusing) reading. Indeed, as you point out, the message is clear-the full-time physician offers the best patient care. I venture to suggest, however, that your statement that present-day physicians are better than those of the past, while correct, does not stand up to the analogy with the golfer, or, for that matter, with any type of sportsman. Sportsmen have improved their performances by achieving greater and better results from the useoftheir natural physiologic and anatomic powers. The effective changes made in the “tools of their trade” have, in fact, been minimal. Physicians, and especially cardiologists, on the other hand, have improved their diagnostic and therapeutic prowessby the increasing availability of new and highly

sophisticated and complicated tools. Indeed, the availability of such tools has, to the regret of many old-timers, resulted in a considerable reduction in the ability to correctly assessa patient’s condition by the application of so-called “physical diagnosis.” Anyone who had the privilege to observe the late Dr. Paul Wood, in London, or, in more recent times, Dr. John Barlow, in Johannesburg, examining a patient and making a correct diagnosis of an often complicated cardiac condition at the bedside, would agree that that type of skill is now rarely applied. While it may be debatable whether or not this affects the overall physicians’ standards, it becomesclear that the modern cardiologist requires entirely different skills to those of former generations. The “Stance and Swing” of the physician have not, in fact, remained the same. Imagine what would happen to a golfer’s performance if he had computer software guiding him during his round, with precise electronic control of the direction travelled by the golf ball, and electronic boosting of the distance it could travel! A good round of golf on an 18 hole course could presumably be achieved in 18 shots! But then, who would want to sponsor a tournament? And how many people would want to play this game? h”ty M. ziofi, MD Jerusalem,Israel 29 May 1991 Ventricular Late Potentials Patients with Acute Myocardial Infarction and Early Thrombolytic Treatment

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We read with interest the study by Zimmermann and co-workers’ demonstrating a lower incidence of late ventricular potentials (LVPs) in patients with acute myocardial infarction (AMI) and early thrombolytic therapy. In our study, we evaluated signal-averaged electrocardiograms of 58 patients with AM1 and thrombolytic therapy us-’ ing a similar recording technique, but qualitative criteria.2 Our recordings, obtained 5 to 10 days afREADERS’ COMMENTS

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"Anything to be done right has got to be done by people that make their living at it".

Atrial Natriuretic Peptide and Cyclic Guanosine Monophosphate Response Cardioversion of Atrial Flutter or nbrillation to Sakti Mookherjee et al* rep...
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