Biomedical subjects
Publications and source records attributed to S R Mittal.
Acute transmural anteroseptal myocardial infarction with acute left ventricular failure can also raise systemic venous pressure in the absence of right ventricular infarction. Right ventricular infarction, therefore, should not be diagnosed simply by the presence of systemic venous congestion.
R wave height, S wave depth and the R/S ratio on electrocardiograms obtained with unipolar oesophageal lead recorded at various levels were studied in 54 cases with emphysema without myocardial infarction and 46 cases with healeeed anteroseptal myocardial infarction. All patients had poor R wave progression in anterior precordial leads. The criterion of R wave height of greater than or equal to 7.5 mm at the ventricular level oesophageal electrocardiogram was most sensitive (85.7%), specific (80%) and accurate (82.4%) for the diagnosis of healed anteroseptal myocardial infarction.
Effects of submaximal exercise were studied on the unipolar esophageal electrocardiogram recorded at ventricular level in 15 patients with essential hypertension who complained of chest discomfort on effort but had negative exercise stress tests using standard leads and lead CM5. Six patients developed horizontal or downsloping depression of the ST segment in the esophageal lead. The ischemic response might result from subcritical coronary stenosis in face of the increased myocardial oxygen demand of hypertrophied myocardium.
We report a case of echocardiographically documented right ventricular infarction in a patient with pre-existing right bundle branch block. The development of right ventricular infarction resulted in concordant T waves in the right-sided chest leads.
The effects of aspirin, dipyridamole and sulfinpyrazone on the development of atherosclerotic lesions in the aorta were studied in cholesterol-fed rabbits. Aspirin and sulfinpyrazone prevented the development of atherosclerosis, whereas dipyridamole-treated animals developed advanced atherosclerotic lesions. As all the three drugs inhibit platelet function, some non-platelet effects are probably responsible for the differences in results. It is felt that dipyridamole should be avoided in hypercholesterolemic individuals.
We report a case of isolated prolapse of the tricuspid valve producing gross incompetence as documented by Doppler examination. This case shows that hemodynamically significant tricuspid regurgitation can occur from isolated prolapse of valvar leaflets.
We describe a case of rheumatic tricuspid stenosis without involvement of the mitral valve. Rheumatic disease of the tricuspid valve is very rare in the absence of concomitant mitral valvar disease. We suggest that the closing pressure at the valve is not the only factor governing localization of the rheumatic process.
Two cases of acute right ventricular infarction associated with acute extensive anterior myocardial infarction in the absence of inferior and/or posterior left ventricular infarction are presented. Such a combination is likely to occur from acute occlusion of the left anterior descending artery in the face of severe narrowing of the infundibular (conus) artery rather than from acute occlusion of the right coronary artery.
Clinical, biochemical and electrocardiographic parameters were studied in 10 patients with uncomplicated acute myocardial infarction with hyperglycemia (but normal glycosylated hemoglobin), and 15 age- and sex-matched patients with uncomplicated acute myocardial infarction without hyperglycemia. The magnitude of hyperglycemia correlated with the site and extent of the infarct, the magnitude of ST-segment elevation and the levels of 17-ketosteroids in the urine.
The effects of maximal hyperventilation and submaximal exercise were studied on the unipolar, esophageal electrocardiogram recorded at ventricular level in 25 'normal' persons and 15 patients having ischemic heart disease with a positive exercise stress test. In normal persons, hyperventilation decreased the amplitude of the R and T waves in 10 and 6 cases, respectively. Submaximal exercise increased the height of the P wave in 8 cases, decreased the amplitude of the R wave in 16 cases and increased the depth of the S wave in 10 cases. In patients with established ischemic heart disease, the esophageal lead could detect exercise-induced posterior ischemia in 8 cases when compared to lead V8, which could detect posterior ischemia in only 3 cases. It is inferred that the esophageal lead placed at the ventricular level is much more sensitive in detecting exercise-induced posterobasal ischemia. Lack of facilities for coronary angiographic and exercise thallium scintigraphic studies limited us from correlating this study and thereby establishing its independent usefulness.
Daily output of urine was measured in three groups of five rabbits each, before and during seven days of oral therapy with nifedipine, verapamil and diltiazem. All the drugs caused significant (P less than 0.001) increases in mean daily output. All the drugs decreased levels of serum sodium but serum potassium levels were lowered only by diltiazem. Inhibition of tubular transport appears to be the important mechanism.
Resting supine and post-provocation (dynamic exercise, isometric exercise and cold pressor) levels of blood pressure were measured in 80 normotensive offspring of normotensive parents (control) and 55 normotensive offspring of parents with essential hypertension. The surface electrocardiogram (including conventional twelve leads, posterior chest leads, right-sided chest leads and bipolar precordial leads) was also recorded in all subjects. Twenty-eight offspring of parents with essential hypertension had their resting and/or post-provocation blood pressure above the upper limit of standard deviation in age- and sex-matched control group. Flat or upright T waves, with either S waves less than 0.2 mV, or S/R ratio less than 2, or T waves equal to or higher than the accompanying R waves in lead V4R, could identify these potential hypertensives with nearly 90% specificity and nearly 75% sensitivity. The criterion had been derived, however, by analysis of the data achieved retrospectively. Therefore, the exact discriminating value of this criterion can be assessed only by a long-term prospective study.
We recorded an esophageal electrocardiogram in a rabbit before and after producing esophageal erosion. The erosion caused an increase in P wave and R wave height and inversion of the T wave. Esophageal erosion can thus cause false positive repolarization changes in the esophageal electrocardiogram.
Explore the source record for details and available documents.
We present an example of bradycardia-dependent aberrancy in the left posterior fascicle in the presence of type I second-degree atrioventricular block occurring in the setting of acute inferior myocardial infarction. The need for prophylactic pacing of such cases is stressed.
Explore the source record for details and available documents.
A case of pseudo-electrical alternation produced by deformation of QRS-T waves by atrial flutter waves is reported. It should be differentiated from the true electrical alternation which has definite diagnostic and prognostic implications.