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Biomedical subjects

B Zen

Publications and source records attributed to B Zen.

15 recordsLinked to original sources
PubMed1993

Increased risk of coronary artery dissection during coronary angiography with 6F catheters.

The use of smaller sized catheters for coronary angiography (CA) is increasing, but little is known about the safety of CA with 6F catheters. The authors reviewed all cases of CA in which 6F and 8F catheters were used in adult patients between 1988 and June, 1990. There were 597 patients in the 6F group and 2,409 patients in the 8F group. Cases of CA with 6F catheters were more likely to be elective (95% vs 87%), to have no coronary disease (35% vs 24%), and to be performed by nonfirst-year fellows (70% vs 54%) when compared with CA with 8F catheters. There were 5 cases of coronary artery dissection. The incidence of dissections was significantly higher (p = .007) in the 6F group (0.67%) than in the 8F group (0.04%). The incidence of dissections was highest for first-year fellows using 6F catheters (1.7%), which was significantly higher (p = .008) than for first-year fellows using 8F catheters. The incidence of major vascular complications tended to be lower (p = .068) in the 6F group (0.17%) than in the 8F group (0.95%). In summary, CA with 6F catheters is associated with an increased risk of coronary artery dissection, particularly with less experienced operators, but tends to be associated with a lower risk of major vascular complications.

Adult↗
PubMed1981

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.

Cerebrovascular Disorders↗
PubMed1981

Electrophysiologic properties of cimetidine in man.

Severe bradycardia has been reported with the use of cimetidine. This observation has been explained by histamines' known action in increasing the contraction rate of the spontaneously beating right atrium, strips of ventricular muscle, and whole heart of guinea pigs. Histamine can also produce cardiac arrhythmias in animals. There is evidence for H2 receptors in the heart. Black and his associates have shown that the characteristic effect of histamine on isolated guinea pig atrium could be selectively blocked by anti-H2 drugs. Thus cimetidine probably can produce a sinus bradycardia by blocking the H2-receptor site in the heart. Recently Engel and Luck reported that 300 mgs of intravenously administered cimetidine did not affect heart rate, sinus node recovery time, or sinoatrial conduction time. These workers concluded that there is insufficient evidence to demonstrate that cimetidine caused appreciable sinus node dysfunction in man. In view of the disparity in these reports, we investigated the effects of 300 mgs of intravenously administered cimetidine on the human conduction system.

Adolescent↗
PubMed1981

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.

Blood Pressure↗
PubMed1980

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 nitroprusside or phentolamine has been shown to improve left ventricular function by reducing both preload and afterload. Sublingual nitroglycerin as well as an infusion of nitroglycerin can also alleviate left ventricular failure in patients with an acute myocardial infarction. Similarly, chronic congestive heart failure patients, irrespective of the etiology, improve hemodynamically after an infusion of phentolamine, nitroprusside or hydralazine. Oral nitrates, phentolamine, and hydralazine have also been demonstrated to produce improvement in chronic heart failure patients. Recently data has become available on the effects of phentolamine, nitroglycerin and nitroprusside 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 to determine what effect intravenously administered hydralazine has on the human conduction system.

Aged↗
PubMed1980

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. 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 hospitalization, and revealed that the abnormalities were reversible with food intake.

Adult↗
PubMed1980

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.

Aged↗
PubMed1980

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 2 1/2-inch strip of 2% nitroglycerin ointment was applied to the chest for half an hour. Pressure recordings and cardiac output were then repeated. 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 resistance. Thus nitroglycerin ointment can be detrimental when given to patients with mitral insufficiency.

Adult↗
PubMed1980

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.

Adult↗
PubMed1979

Inappropriate slowing of the pacemaker rate with programmable 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.

Electrocardiography↗