Biomedical subjects
Publications and source records attributed to J P Sethi.
An unusual tear in an Inoue balloon during dilatation of calcific mitral stenosis is presented and its mechanisms discussed. An abnormal sequence of inflation indicates a possible tear.
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.
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 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.
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.
This study included 25 hypertensive patients with "normal" standard 12-lead scalar electrocardiogram and an equal number of age- and sex-matched controls. We recorded routine twelve leads, posterior chest leads, ensiform lead, right-sided precordial leads, lead CM5 and oesophageal electrocardiogram at different levels in all individuals. In addition we recorded an unconventional unipolar lead with the chest electrode placed on the thoracic seven spine. We also recorded some unconventional bipolar leads, in each instance using V5 as the positive electrode and the T7 spine, or the oesophageal electrode as negative. We observed that the T wave height of 20% or less of R wave amplitude in lead I was highly specific (92%) and sensitive (76%) in detecting early left ventricular hypertrophy in hypertensive patients, with the standard 12-lead electrocardiogram considered "normal" by conventional criteria. The T wave amplitude of 15% or less of the accompanying QRS in lead V6 was nearly equally diagnostic (specificity 88% and sensitivity 68%). An S wave of 0.3 mV or more in the bipolar lead recorded with the positive electrode at V5 and the negative electrode on T7 spine was also highly specific (80%) and sensitive (72%). Isoelectric or inverted T wave in lead V8, ST segment depression and T wave inversion in lead CM5 and ST segment depression in the bipolar lead recorded with the positive electrode at the V5 position and negative electrode at the atrial level of the oesophagus were highly specific (100%) but had a low sensitivity (40, 36, 16, and 28%, respectively). Combined lead V8 and lead I further improved the sensitivity to 96% without decreasing the specificity.
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