Sunil K. Das

Prognostic usefulness of programmed ventricular stimulation in idiopathic dilated cardiomyopathy without symptomatic ventricular arrhythmias

Twenty-four patients, mean age 42 years, with idiopathic dilated cardiomyopathy (DC) and no history of symptomatic ventricular arrhythmias underwent right ventricular programmed stimulation with up to 3 extrastimuli. Ventricular tachycardia (VT) was induced in 8 patients and ventricular fibrillation (VF) in 2. The VT was unimorphic in 2 and polymorphic in 6. No significant differences were noted between patients in whom arrhythmias were inducible and and those in whom they were not with regard to age, symptomatic class, arrhythmia severity or hemodynamic indexes. Over a mean follow-up of 12 months, 4 patients died, 3 suddenly and 1 with progressive heart failure. Only 1 of the 3 who died suddenly had inducible VT. One other patient with induced sustained unimorphic VT later presented with spontaneous sustained VT similar in rate and configuration to induced VT. In conclusion, VT or VF may be induced in approximately 40% of patients with DC and no history of symptomatic VT or VF. Inducibility of polymorphic VT or VF does not correlate with clinical or hemodynamic variables or with the risk of sudden death. However, induction of unimorphic VT may predict later occurrence of spontaneous unimorphic VT.

Prospective, double-blind, placebo-controlled trial of low-dose amiodarone in patients with severe heart failure and asymptomatic frequent ventricular ectopy

Sudden cardiac death is a common cause of mortality in patients with congestive heart failure. To determine if low-dose amiodarone could reduce sudden death among these patients, a prospective, placebo-controlled, double-blind pilot trial was conducted. One hundred one patients with ejection fractions less than 30%, New York Heart Association class III or IV symptoms, and frequent but asymptomatic spontaneous ventricular ectopy (Lown class II to V) were randomly assigned to treatment with low-dose amiodarone (400 mg/day for 4 weeks and then 200 mg/day) or placebo. Mean follow-up was 357 days (range 4 to 1009 days). Side effects were infrequent and there was no difference in the incidence of side effects between the treatment groups. The frequency of spontaneous ventricular ectopy in the group receiving amiodarone fell from 4992 +/- 1240 beats/24 hours at baseline to 1135 +/- 494 beats/24 hours after 1 month of treatment (p = 0.02) and remained low after 6 months, while there was no change in ventricular ectopy among the patients receiving placebo. Despite the reduction in ectopy, there was no improvement in mortality or decrease in the incidence of sudden death. One-year mortality by Kaplan-Meier analysis was 28% in the group receiving amiodarone and 19% in the group receiving placebo (p = NS). One-year mortality in patients with greater than 75% reduction in ventricular ectopy after 1 month of treatment was 31% versus 17% in patients with less than or equal to 75% ectopic suppression (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies against heart muscle and nuclear constituents in cardiomyopathy

Abstract The prevalence of HAB and ANA was determined in eight patients with idiopathic hypertrophic subaortic stenosis (IHSS) and 35 patients with cardiomyopathy (CM). HAB was found in 88 per cent of patients with IHSS and in 17 per cent of those with CM. Antinuclear antibody was found in 63 per cent of patients with IHSS and 43 per cent of those with CM. Aging alone was not responsible for the high prevalence of ANA in the former group, but may be partly so in the latter. There was an increased tendency for women in both groups to have ANA. An increased serum concentration of IgM was also observed in women in the IHSS and CM groups. Serum concentrations of IgG and IgA, precipitating antibodies to nuclear constituents, rheumatoid factors, and a positive serologic test for syphilis were not increased in patients with idiopathic cardiomyopathy. Positivity to HAB and ANA did not remain constant and was not present frequently in sera in follow-up studies of these patients. No instance of a negative test becoming positive was recorded for either HAB or ANA. The high prevalence of ANA in patients with IHSS and CM and an increased prevalence of HAB in patients with IHSS may suggest that an autoimmune disturbance is operative in these forms of cardiomyopathy.

Neurohumoral activation during exercise in congestive heart failure.

Neurohumoral factors were assessed in 14 subjects with chronic, stable New York Heart Association functional class II or III congestive heart failure and nine comparably aged normal subjects at rest and during moderate (50 W) and strenuous (100 W) upright exercise. Heart failure was associated with elevated plasma renin activity and plasma antidiuretic hormone (ADH) concentrations at rest. However, plasma renin activity almost doubled (from 4.7 +/- 0.6 to 8.4 +/- 1.1 ng/ml per hour) during strenuous exercise in subjects with heart failure, and changed only minimally in normal control subjects. Plasma ADH concentration did not change during exercise in the presence of heart failure, but rose in normal subjects during strenuous exercise to levels comparable to those of subjects with heart failure. Similar plasma osmolality values were present in both groups. Circulating norepinephrine concentrations were insignificantly elevated by heart failure both at rest and during exercise, and plasma epinephrine concentrations were similar. These findings suggest independent neurohumoral activation during exercise in the presence of congestive heart failure, with predominant activation of the renin-angiotensin-aldosterone axis.

Interventricular Septal Defect Analysis of 415 Catheterized Cases, Ninety with Serial Hemodynamic Studies

Four hundred fifteen patients with interventricular septal defect, proved at cardiac catheterization, have been followed for 1,407 patient years. As a group, they demonstrated marked growth failure in early childhood, which was more striking for weight than height. Ninety patients had serial hemodynamic studies without intervening cardiovascular surgery. Eight demonstrated spontaneous functional closure of their defect; only one progressed to the Eisenmenger syndrome. No patient with initially normal pressure developed pulmonary hypertension. Patients with initial pulmonary hypertension more commonly demonstrated regression than progression of the hypertension. Six patients developed bacterial endocarditis; all recovered. There was a frequent association (11 per cent) between interventricular septal defect and right ventricular outflow obstruction. Some patients developed increasing right ventricular outflow obstruction during the study. Eighteen patients with predominant right-to-left shunt were studied. Seventeen were cyanotic at the time of the initial study. The incidence of cyanosis was equal in the two sexes but females developed it later in life than males.Twenty-nine patients have died. Twenty-two deaths resulted from operative procedures; seven from the natural course of the disease. The principal factors associated with operative mortality was the presence of pulmonary hypertension and surgical repair before age 5. There were no operative deaths in patients with pulmonary artery systolic pressure below 65 mm. Hg. One patient died of progressive pulmonary hypertension 6 years after successful surgical closure of his defect.There is a great need for more information concerning the natural course of this disease in all age groups, both in the unoperated patient and in patients whose defects have been surgically closed.

Aneurysm of the Membranous Septum with Interventricular Septal Defect Producing Right Ventricular Outflow Obstruction

The second known case of aneurysm of the membranous interventricular septum simulating infundibular pulmonic stenosis associated with an interventricular septal defect is described. Hemodynamic studies before and after successful surgical correction of both lesions are presented. The current literature on the subject is briefly reviewed.

Effects of β-Adrenergic Blocking Therapy on Left Ventricular Diastolic Relaxation Properties in Patients With Dilated Cardiomyopathy

Background—The hemodynamic mechanism for the improvement in left ventricle (LV) end-diastolic pressure in cardiomyopathy patients treated with β-adrenergic blocking agents is controversial. We hypothesized that the salutary effect of this kind of therapy on LV end-diastolic pressure would be indicative of an improvement in late, passive diastolic relaxation properties. Methods and Results—We studied 14 cardiomyopathy patients in normal sinus rhythm with no arteriographic evidence of coronary artery disease and an LV ejection fraction of ≤40% by radionuclide angiography both before and after 6 months of metoprolol therapy with simultaneous micromanometry and biplane cineventriculography. Four comparable patients who were not treated with metoprolol were studied in a similar fashion and served as control subjects. In those receiving metoprolol, LV end-diastolic pressure decreased (P=0.001). The isovolumic relaxation index, τln, shortened (P=0.03). In a similar fashion, the LV chamber stiffness constant, κ, ...

Immunoglobulin Binding in Cardiomyopathic Hearts

Bound gamma globulin was demonstrated by the direct immunofluorescent technique in heart tissue from three patients with severe congestive cardiomyopathy. In two of these patients complement (&bgr;1C) was also bound to the heart muscle. Heart tissue from one of six patients who died of myocardial infarction showed a trace of bound gamma globulin, but no bound complement. During life, the heart in advanced cardiomyopathy may preferentially fix heart-reactive immunoglobulins to specific sarcolemmal and subsarcolemmal antigens, and antiheart antibody may not be detectable in the serum.

Antiheart antibodies in patients with systemic lupus erythematosus.

Sera from 32 consecutive patients with systemic lupus erythematosus were examined for antiheart antibodies by an immunofluorescent technique. Results were compared to those obtained with sera from five control groups of patients. Sixty-three per cent of the patients with systemic lupus erythematosus had antiheart antibodies. Antibodies were present in equal frequency in those with and those without clinical cardiac disease and were found in six of seven patients with congestive heart failure. Although both subsarcolemmal and sarcolemmal patterns of immunofluorescence were seen, the former was predominant. The clinical significance of this high prevalence of antiheart antibodies in systemic lupus erythematosus is not clear. They may represent an immunologic response to release into the circulation of altered myocardial antigens.

ω-123I-Hexadecanoic acid metabolic probe of cardiomypathy

The utility of ω-123I-hexadecanoic acid myocardial scintigraphy as a metabolic probe of cardiomyopathies was investigated. Sixteen patients with a variety of cardiomyopathies and myopathies that involve cardiac muscle and ten volunteers were imaged in the postabsorptive state in a 40° LAO projection after a standard dose of ω-123I-hexadecanoic acid. An elimination T1/2 was calculated from the left ventricular myocardial time-activity curve. An uptake index, corrected for chest wall attenuation, was also computed in 7 of 10 volunteers and 8 of 16 patients.Of the 16 patients, only 2 had distinctly abnormal ω-123I-hexadecanoic acid myocardial tracer kinetics. The first patient had a metabolic disorder of which cartine deficiency was one component. The second patient had endocardial fibroelastosis, a process which has been linked to disorders which deprive the myocardium of oxygen and energy. Therefore, the cardiomyopathy may have been caused by some abnormality of cardiac metabolism other than carnitine deficiency. Although of limited utility in the overall cardiomyopathic population, ω-123I-hexadecanoic acid myocardial scintigraphy should be further investigated as a screening test for carnitine deficiency and related metabolic abnormalities in patients at risk.