B.K. Singh

Evaluation of Cardiac Conduction in Anorexia Nervosa

Anorexia nervosa is a disorder characterized by excessive dieting, a morbid fear of becoming obese, a distorted body image and amenorrhea in women, The condition is seen chiefly in girls and young women but also occurs in men. Death in anorexia nervosa may be sudden, and the mortality rate is the highest of any psychiatric disease.1 Despite investigations of its endocrine and psychiatric manifestations, little has been written about cardiac conduction in this entity. We report a patient with anorexia nervosa who presented with syncope due to a sinus bradycardia. His bundle electrograms were performed during the course of her hospilalization, and revealed that the abnormalities were reversible with food intake.

Inappropriate Slowing of the Pacemaker Rate with Programmahle Demand Pacemaker

A 60‐year‐old male with a programmable pacemaker developed inappropriate slowing of the pacemaker rate. This was due to oversensing of the T waves combined with after‐potential sensing. This does not represent generator malfunction and can usually be corrected by reprogramming the pulse duration, or the milliamperage.

T-wave changes with intermittent left bundle branch block.

A 70-year-old woman was found to have an intermittent left bundle branch block. When her electrocardiogram showed normal conduction, T-wave inversions in leads V1-V3 appeared. These alterations suggested an anteroseptal infarction. However, the patient was asymptomatic, and the serum enzymes, technetium 99m pyrophosphate scan, and the thalium 201 scan were all negative. Thus the LBBB itself can produce T-wave in versions in the right precordial leads during the normal conduction phase which may simulate an acute myocardial infarction.

Effect of Nitroglycerin Ointment on Hemodynamics in Patients With Mitral Insufficiency

A reduction in impedance or afterload produces beneficial hemodynamic effects in patients with mitral regurgitation. This mechanism has been studied via intravenous infusion of nitroprusside, phentolamine, and hydralazine. But there is little information on the effect of nitroglycerin ointment in patients with mitral insufficiency. Thus 6 patients with mitral insufficiency underwent right and left heart catheterization. After the control hemodynamic measurements were recorded, a 21/2-inch strip of 2% nitroglycerin ointment was applied to the chest for half an hour. Pressure recordings and cardiac output were then re peated. The control cardiac index fell from 2.79 to a treatment value of 2.05 L/ min/m2 (P < 0.01), while the stroke index also decreased from 29 to 22 ml/ beat/m2 (P < 0.05). There was a nonsignificant increase in peripheral resis tance. Thus nitroglycerin ointment can be detrimental when given to patients with mitral insufficiency.

Cardiac Effects of Alcohol

There is little information on the echocardiographic evaluation of left ventricular performance after the ingestion of alcohol. Therefore, we obtained echocardiograms and systolic time intervals in 9 normal subjects before and after a cocktail party. These subjects drank 5-6 ounces of 87 proof whiskey during the party. An additional 19 normal subjects drank 3 ounces of 87 proof whiskey and had similar studies performed. The results of the study with 5-6 ounces of alcohol are in Table 3. The 19 subjects who drank 3 ounces of alcohol showed no statistical changes except that the systolic ejection time fell from a control of 0.31 +/- 03 (see formula in text) to 0.30 +/- 0.4 (P less than 0.05). These data indicate that 5-6 ounces of whiskey can depress left ventricular function in normal subjects.

Electrophysiologic Properties of Hydralazine in Man

There is considerable interest in selecting the proper drug to preserve the ischemic myocardium, or twilight zone, in a patient with a recent myocardial infarction, Vasodilator therapy with an infusion of nitroprusside1 or phentolamine2,3 has been shown to improve left ventricular function by reducing both preload and afterload. Sublingual nitroglycerin4 as well as an infusion of nitroglycerin5 can also alleviate left ventricular failure in patients with an acute myocardial infarction. Similarly, chronic congestive heart failure patients, irrespective of the etiology, improve hemodynam‐ically after an infusion of phentolamine,6,7 nitroprusside8 or hydralazine.9 Oral nitrates,10 phentolamine,11 and hydralazine12 have also been demonstrated to produce improvement in chronic heart failure patients. Recently data has become available on the effects of phentolamine.13 nitroglycerin14 and nitroprusside15 on cardiac conduction in man. However there is no information on the electrophysiological properties of hydralazine in man. The present study involving 12 human subjects was undertaken lo determine what effect iniravenously administered hydralazine has on the human conduction system.

Electrocardiographic normalization after cerebral vascular accident

A 59 year old female sustained an anterior subendocardial infarction with deep T wave inversions in leads I, AVL and V2-V6. She subsequently developed a cerebral vascular accident. The ECG now revealed upright T waves in the leads that previously showed deep T wave inversions. A review of the literature failed to reveal a similar case of normalization of the ECG after a cerebral vascular accident.

Enhancement of phentolamine by nitrates in patients with congestive heart failure.

Phentolamine dilates the resistance bed and to a lesser degree the capacitance bed, while the nitrates have the opposite action. Therefore, in 7 patients with congestive heart failure due to congestive cardiomyopathy, hemodynamic measurements were made using a Swan Ganz thermodilution catheter and cardiac output computer. The patients received 5 mg of an IV infusion of phentolamine administered at 0.3 mg/minute. At the end of the infusion, the pressures and cardiac output were obtained. Then, 2 1/2 inches of nitroglycerin ointment was applied to the chest, and the hemodynamic parameters were obtained 30 minutes later. Phentolamine produced a significant reduction in the right and left ventricular filling pressures and a significant increase in the cardiac output. The hemodynamic effects of phentolamine are known to persist for an hour or longer. The addition of nitroglycerin ointment led to a further reduction in the right and left ventricular filling pressures. Thus, the combination of phentolamine and nitrates can be effectively used in the treatment of congestive heart failure.