M. L. Bhatia

Hemodynamic Effects of Chronic Severe Anemia

Data on the cardiac output and circulatory dynamics obtained by cardiac catheter studies in 51 subjects with chronic severe anemia are presented. Patients are divided into two groups: group A consists of 26 subjects with an average hemoglobin value of 3.0 Gm. per 100 ml. (range 1.5 to 3.8 Gm.); group B, 25 patients with a hemoglobin level of 4.0 to 6.5 Gm., average 4.5 Gm.Group A subjects have a somewhat faster heart rate (99 against 92 a minute), higher cardiac index (8.0 versus 6.3 liters per minute per square meter), and stroke index (88and 68 ml. per beat per square meter) than group B patients.The oxygen consumption values in both groups are normal (average 158 and 160 ml. per minute per square meter), while more oxygen is extracted by the tissue in group A subjects (61 and 53 per cent) whereas less oxygen is transported to the tissue (261 and 321 ml. per minute per square meter).The stroke volume seems to bear a closer relationship to the high cardiac output than such other parameters as heart rate, right heart filling pressure, and velocity of blood flow. Apparently the presence of slow heart rate does not negate high cardiac output.Data also suggest that systemic vascular resistance may play an important role in the high cardiac output as the two are inversely related, and by increasing the peripheral arterial pressure the output can be significantly reduced.Restudy data after the treatment of the anemia (hemoglobin 10.0 to 12.5 Gm. per 100 ml.) show appreciable reduction in the cardiac output and in the right heart filling pressure, increase in the peripheral vascular resistance and oxygen transport values, and widening of the arteriovenous oxygen differences with concomitant decrease in the oxygen extraction by the tissue.

Effect of Frusemide on Pulmonary Blood Volume

Intracardiac frusemide given to seven patients recovering from high-altitude pulmonary oedema caused a significant reduction in the pulmonary blood volume before the onset of diuresis. This supports the suggestion that the mobilization of fluid from the pulmonary circuit is responsible for the relief of symptoms in some patients with pulmonary oedema even when a diuresis does not occur.

Evaluation of patients with bundle branch block and "unexplained" syncope: a study based on comprehensive electrophysiologic testing and ajmaline stress.

Thirty‐five patients with bundle branch block (BBB) and unexplained syncope underwent electrophysiologic study (EPS) including programmed ventricular stimulation and ajmaline administration (1 mg/kg, IV) to induce inra‐His block. A prolonged HV interval (>55 ms) was present in 16 of the 35 patients. Ajmaline‐induced HV block occurred in 12 patients (complete HV block in 10, and 2:1 HV block in two). Monomorphic ventricular tachycardia (VTJ was inducible in nine (25.7%) and polymorphic VT in two patients (5.7%). Left ventricular ejection fraction (LVEFJ was less than 40% in five patients (45.5%) with inducible VT. Two patients had an unexpected co‐existence o/inducible HV block and VT. The remaining 14 patients (40%) had no detectable abnormality. The incidence of inducible VT was higher (45% vs 13.3%), and the presence of negative studies was lower (30% vs 53.3%) in patients with structural heart disease (n = 20), when compared to those with no significant heart disease (n = 15) (differences not significant [NS]). During a mean follow‐up period of 16.5 ± 9.2 months, all the patients with inducible HV block have been asymptomatic after having received permanent pacemakers. Patients with inducible monomorphic VT (except one with poor left ventricular function who died suddenly) have also been asymptomatic on antiarrhythmic drugs. Of the remaining patients, seven with normal EPS, two with prolonged HV intervals but no inducible HV block (despite being given permanent pacemakers) and one patient with polymorphic VT on antiarrhythmic drugs continue to have recurrent syncope. Approximately 60% of patients with BBB and unexplained syncope have clinically significant electrophysiologic abnormalities. VT accounts for symptoms in a significant number of patients. Ajmaline stress is a useful adjunct to unmask infra‐His block, and some patients have more than one abnormality. Long‐term management guided by detailed EPS is generally successful in preventing recurrent syncope in patients with inducible arrhythmias such as HV block and monomorphic VT.

Circulatory effects of pregnancy.

Abstract Data on the cardiac output and related circulatory parameters obtained in 29 normal Indian women by 82 studies during different phases of their pregnancies are presented. Maximum increase in the cardiac output, stroke volume, central blood volume and left ventricular work-load, and maximum reduction of the peripheral vascular resistance occurred during the twenty-eighth to thirty-fourth weeks of pregnancy. The main determinants of the high cardiac output are increased stroke volume and decreased vascular resistance. The vascular resistance-lowering effect of progesterone may, in part, be responsible for the maximum cardiac output a few weeks before and not at term. Because of the increased cardiac load during twenty-eighth to thirty-fourth weeks, heart disease patients are more apt to go into congestive heart failure during this phase rather than at term or parturition. It is suggested that attending physicians should be aware of this unusual circulatory adjustments.

Myocardial infarction in young Indian patients: Risk factors and coronary arteriographic profile

One hundred four patients (101 men, three women), under 40 years of age, with myocardial infarction (MI), underwent coronary arteriography. Eighty patients had significant obstructive coronary artery disease (CAD) (group 1), 23 had normal coronary arteries (group 2), and one patient had coronary ostial stenosis as a result of nonspecific aortoarteritis (group 3). Coronary risk factors in group 1 included smoking (76.2%), hypercholesterolemia (36.3%), hypertension (32.5%), positive family history (28.7%), and diabetes mellitus (5%). Multiple risk factors were frequent (56.2%). Smoking was common (p less than 0.01) and diabetes mellitus less frequent (p less than 0.05) as compared to older (greater than 40 years) patients with MI and arteriographically proved CAD. The frequency of one-, two-, and three-vessel disease was 33.7%, 26.2%, and 40%, respectively, in group 1. Group 2 patients were almost devoid of coronary risk factors. The only group 3 patient had left coronary ostial stenosis with no risk factors. Similar to their counterparts in developed countries, young Indian patients with MI and obstructive CAD have a high frequency of coronary risk factors, especially smoking and severe multiple-vessel disease. Since normal coronary arteriograms are also frequent in this setting, a detailed evaluation is recommended for purposes of prognosis and management.

Significance of advanced atrioventricular block in acute inferior myocardial infarction — a study based on ventricular function and Holter monitoring

Eighty-two consecutive patients with a first inferior wall acute myocardial infarction were evaluated by radionuclide angiography and 24-hour Holter monitoring during their hospital stay. The patients were divided into two groups. The first group (n = 28) had advanced atrioventricular block, while the second group (n = 54) were without atrioventricular block. The patients with advanced block had lower left ventricular (49 +/- 12% vs. 55 +/- 14%, P less than 0.05) and right ventricular ejection fraction (26 +/- 10% vs. 43 +/- 11%, P less than 0.001) than those with normal atrioventricular conduction. The atrioventricular block disappeared spontaneously in all of them. The hospital mortality of the patients with advanced block and those without advanced block was 10.7 and 5.5%, respectively (P = NS). Pre-discharge 24-hour Holter monitoring done in all survivors revealed isolated ventricular ectopics (Lown grade I, II, III) in 44% of patients who had had advanced block and 43.1% of patients without advanced block (P = NS). Complex ventricular ectopics (Lown grade IVa, IVb), however, were recorded in significantly more patients with advanced block as compared to patients without advanced block (36 vs. 7.8%, P less than 0.01). Most patients with complex ventricular ectopics in both groups had impaired left or right ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of Antimyosin Antibody Imaging for the Detection of Active Rheumatic Myocarditis

Myocarditis constitutes an important component of rheumatic carditis. Antimyosin scintigraphy, which allows noninvasive assessment of myocyte damage, can be used for documentation of cardiac involvement in patients with rheumatic fever where clinical diagnosis is not unequivocal.

Ajmaline-induced torsade de pointes.

A patient with primary myocardial disease and left bundle-branch block who developed marked QT prolongation and torsade de pointes following an intravenous injection of ajmaline during an electrophysiologic study is reported. The patient could be resuscitated successfully 1 h after the onset of tachycardia.

Doppler echocardiographic evaluation of normal and thrombosed Björk-Shiley mitral prosthetic valves

Doppler echocardiographic characteristics of 75 normally functioning Björk-Shiley mitral prostheses were studied in patients whose valvar function was considered normal by clinical and fluoroscopic evaluation. The mean Doppler peak and end-diastolic gradients were 9.01 +/- 3.23 mm Hg, and 2.36 +/- 1.0 mm Hg, respectively. The mean area of the mitral valve calculated by the half-time method was 2.58 +/- 0.38 cm2. No significant difference between the various Doppler parameters was found for the two different valve sizes (25 and 27 mm) studied. Trivial mitral regurgitation was detected in 21 (28%) cases. Doppler echocardiography was performed in six patients with suspected malfunction of the Björk-Shiley mitral prosthesis subsequently confirmed at operation. The end-diastolic gradients in the six patients were 16, 20, 10, 14, 16, and 24 mm Hg, respectively. The calculated areas of the mitral valve were 1.57, 1.37, 1.3, 1.5, 1.46, and 1.3 cm2, respectively. The values of the gradient and calculated areas in malfunctioning valves were very different from those found in normally functioning Björk-Shiley mitral prostheses. It is concluded that Doppler echocardiography is a very useful noninvasive technique for the study of the function of the Björk-Shiley mitral prosthesis and provides quantitative information regarding pressure gradients and valvar area.

Response of pulmonary blood volume to 64 to 114 weeks of intermittent stay at high altitudes

Abstract Data on the pulmonary blood volume and related hemodynamic parameters obtained by cardiac catheter studies in 11 healthy volunteers before and after 64 to 114 weeks of intermittent stay at an altitude of 14,500 feet have been presented. The heart rate decreased by 13 per cent, pulmonary flow increased by 60 per cent, and stroke volume increased by 77 per cent. The central and pulmonary blood volumes showed an average increase of 97 and 76 per cent, respectively. Pulmonary arterial and left atrial mean pressure values showed some elevation but remained within the upper limits of our normal values. When the increases in the flow and blood volumes were related to the duration of total and continuous stays at high altitude, better correlation was apparent with the last continuous stay prior to the restudy than with the total stay. Although central blood volume and pulmonary flow increased within 25 weeks and remained increased, with some fluctuation, the increase in the pulmonary blood volume was apparent only after 25 weeks of stay, after which it increased progressively. It is suggested that increased pulmonary flow and pulmonary blood volume but normal pulmonary arterial pressure, as seen here, may represent a form of successful adaptation in temporary residents of high altitude.