Biomedical subjects

N de Soyza

Publications and source records attributed to N de Soyza.

At least 19 recordsLinked to original sources

PubMed1988

Sustained therapeutic efficacy and safety of oral propafenone for treatment of chronic ventricular arrhythmias: a 2-year experience.

Thirty-two men with chronic ventricular arrhythmias responded to propafenone, a new potent antiarrhythmic agent, in short-term trials with 85% or greater reduction of total ventricular premature complexes (VPCs) per hour, 95% or greater reduction of ventricular couplets (VCs) per hour, and 100% abolition of ventricular tachycardia (VT) beats per 24 hours. These patients were continued on long-term propafenone therapy to assess sustained therapeutic efficacy and safety. Thirty patients completed 1 year and 26 patients completed 2 years of testing with this agent; one patient died of sudden death and another died of a noncardiac cause. Although there were significantly fewer patient responders at 1 and 2 years, the majority of patients (greater than 79%) continued to respond optimally to propafenone. Side effects were minor and included bitter taste, dizziness, congestive heart failure, fatigue, and significant prolongation of the PR and QRS intervals. Propafenone has sustained antiarrhythmic efficacy after 2 years without serious toxicity.

Aged↗

PubMed1985

Sensitivity of electrocardiographic criteria for left ventricular hypertrophy according to type of cardiac disease.

The sensitivity of 30 electrocardiographic criteria for left ventricular (LV) hypertrophy, isolated or combined, was examined to determine the relation to the underlying disease. Patients with coronary artery disease (CAD), systemic hypertension, valvular heart disease and cardiomyopathy were evaluated. A cardiac partition technique was used to define ventricular hypertrophy. Single electrocardiographic criteria often showed high sensitivity for 1 disease state, but not for others. Precordial voltage criteria were most sensitive for those with hypertensive and valvular disease. A QRS axis of more than -30 degrees occurred most often in patients with CAD. Both left atrial abnormality and abnormal T-wave inversion of more than 1 mm in V6 occurred with a high sensitivity in general; however, T-wave inversion of more than 1 mm in V6 had a low sensitivity in cardiomyopathy. Methods using combinations of various electrocardiographic criteria improved sensitivity. Using these methods, sensitivity of the electrocardiogram for LV hypertrophy was excellent for patients with systemic hypertension and valvular heart disease and acceptable by usual standards for patients with CAD and cardiomyopathy. Because the use of a single criterion is often ineffective, methods using multiple electrocardiographic criteria to detect LV hypertrophy are recommended when the patients under study have diverse cardiac diseases.

Adult↗

PubMed1985

Coronary artery atherosclerosis observed in men over 14 consecutive years.

The incidence of cardiovascular death and myocardial infarction associated with ischemic heart disease has declined over the past 15 years. Whether this is associated with a decrease in the severity of coronary atherosclerosis is unknown. The extent of coronary atherosclerosis in men was determined by postmortem coronary angiography in 505 patients over an observation period of 14 years. Patients were divided into those with ischemic heart disease (42%) and those without (58%). Mean coronary scores showed no significant trends over the 14-year period in those without ischemic heart disease and for the last 10 years in those with ischemic heart disease. In those few patients evaluated early in the study with ischemic heart disease, a significantly lower coronary score was found compared to subsequent years. This study was performed during an era of declining cardiovascular death rates and a declining incidence of myocardial infarction, and suggests that this decline may relate to favorable changes in pathogenesis rather than to a decrease in extent of coronary atherosclerosis.

Adult↗

PubMed1985

Acebutolol for premature ventricular contractions: short- and long-term effects.

The safety and efficacy of oral acebutolol therapy for the suppression of premature ventricular contractions (PVCs) were assessed in two clinical trials pooled for analysis. Thirty-two patients suffering from organic heart disease, who had experienced an average of greater than or equal to 10 PVCs/h (range 14 to 996 three times a day) on Holter monitoring during a 24-hour baseline study period, were given acebutolol (100 mg three times a day to 400 mg four times a day) over 4 weeks. Three patients were withdrawn from the study for administrative reasons, and four patients were excluded from the efficacy analysis. Of the 25 remaining patients (24 men, 1 woman; mean age 56 years, range 37 to 69), 18 (72%) experienced some reduction in PVCs from the second through the fourth week of therapy. Eleven patients (44%) experienced clinically significant reductions (greater than or equal to 75%) in PVCs. The onset of the antiarrhythmic effect of acebutolol was within 7 days of administration. Transient mild to moderate side effects were noted in eight patients. Significant correlations (p less than 0.001) were observed between the mean daily dose of acebutolol and (1) mean blood levels, (2) reduction in PVCs, and (3) reduction in resting heart rate. The average daily dose of acebutolol ranged from 304 to 1060 mg. In nine patients receiving acebutolol in a 12-month open-label extension, both efficacy and safety were maintained. This study confirms that oral acebutolol therapy in both safe and efficacious for suppressing PVCs in patients with organic heart disease.

Acebutolol↗

PubMed1984

Reevaluation of electrocardiographic criteria for left, right and combined cardiac ventricular hypertrophy.

Cardiac chamber weight was determined at necropsy in 323 men to develop correlative studies of electrocardiographic criteria for ventricular hypertrophy. Thirty recommended criteria for left ventricular (LV) hypertrophy, 10 for right ventricular (RV) hypertrophy, and combinations of both criteria for combined hypertrophy were evaluated. Four methods for electrocardiographic diagnosis of LV hypertrophy were derived: (1) a modification of the Romhilt-Estes point system; (2) the presence of any 1 of 3 criteria: (a) S V1 + R V5 or V6 greater than 35 mm, (b) left atrial abnormality, or (c) intrinsicoid deflection in lead V5 or V6 greater than or equal to 0.05 second; (3) a combination of any 2 criteria or of 1 criterion (above) plus at least 1 of the following 3 additional criteria: (a) left-axis deviation greater than -30 degrees, (b) QRS duration greater than 0.09 second, or (c) T-wave inversion in lead V6 of 1 mm or more; and (4) the use of a single criterion--left atrial abnormality. Sensitivity varied from 57 to 66% and specificity from 85 to 93% among these 4 methods. Myocardial infarction increased sensitivity of the foregoing methods, but the specificity was reduced. Method 2 is preferred for the electrocardiographic diagnosis of LV hypertrophy. Two methods were useful for right ventricular (RV) hypertrophy: (1) the use of any 1 of 4 criteria: (a) R/S ratio in lead V5 or V6 less than or equal to 1; (b) S V5 or V6 greater than or equal to 7 mm; (c) right-axis deviation of more than +90 degrees, or (d) P pulmonale; and (2) use of any 2 combinations of the foregoing criteria. Sensitivity ranged from 18 to 43% and specificity from 83 to 95%. Combined hypertrophy was best diagnosed using left atrial abnormality as the sole criteria of LV hypertrophy, plus any 1 of 3 criteria of RV hypertrophy: (a) R/S ratio in lead V5 or V6 less than or equal to 1, (b) S V5 or V6 greater than or equal to 7 mm, or (c) right axis deviation greater than +90 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1984

Effect of propafenone in patients with stable ventricular arrhythmias.

Thirty patients with clinically significant ventricular ectopy were treated with propafenone, a new potent antiarrhythmic agent with membrane stabilizing action. Patients had a minimum mean of greater than 30 ventricular premature beats per hour documented by continuous 48-hour ambulatory ECG recording. Twenty-five patients qualified as responders, defined as greater than 85% reduction of ventricular ectopy compared to baseline, and completed a double-blind placebo-crossover phase. Significant reduction in single ventricular ectopy per hour, paired ventricular ectopy per hour, and ventricular tachycardia beats per hour were observed. Almost total abolition of ventricular tachycardia and paired ventricular ectopy was achieved. Side effects were minimal and well tolerated. A significant prolongation of the PR interval occurred. QRS prolongation and prolongation of the corrected QT interval was observed in some patients, with new left bundle branch block developing in two patients. Long-term efficacy and safety studies will be necessary to determine the ultimate role of this new agent in the selection of antiarrhythmic therapy, but these initial results are encouraging.

Adult↗

PubMed1983

Left atrial abnormality as an electrocardiographic criterion for the diagnosis of left ventricular hypertrophy in the presence of right bundle branch block.

Left atrial (LA) abnormality determined from precordial lead V1 was assessed by 2 observers as a criterion of left ventricular (LV) hypertrophy in the presence of right bundle branch block (BBB) in 23 patients. The presence of LV hypertrophy was confirmed from a postmortem cardiac partition technique and defined at 2 levels of confidence: probable and definite hypertrophy. Observers reliably differentiated between the hypertrophied and normal-sized ventricle in the presence of right BBB by using LA abnormality as an electrocardiographic criterion. When defined as definite hypertrophy, observer 1 correctly identified LV hypertrophy in 78% of the cases and observer 2 in 67% of the cases. False-positive results were present in 21% of cases by observer 1 and 14% by observer 2. Comparable results were achieved when a definition of probable hypertrophy was used. Observer performance of recognition of LA abnormality in this study was satisfactory with 91% agreement between observers. Our results are comparable and in some instances superior to conventional criteria commonly recommended to diagnose LV hypertrophy on the electrocardiogram without right BBB.

Aged↗

PubMed1983

Quantitation of fibrosis of the heart in chronic obstructive pulmonary disease with and without cor pulmonale.

This study examined the hearts of 55 patients dying of chronic obstructive pulmonary disease, with and without cor pulmonale, quantitated histologically the degree of myocardial fibrosis in the left and right ventricle, and determined the relationship to associated disease states. Comparison has been made to a control group of 17 patients free of cardiopulmonary disease. Patients with associated and advanced ischemic heart disease, as proved by marked atherosclerosis and myocardial infarction, have significantly increased myocardial fibrosis throughout all layers of the left ventricular wall in comparison to control patients or patients with chronic obstructive pulmonary disease free of associated cardiac disease. Right ventricular fibrosis was not significantly increased; however, one case showed a marked degree of fibrosis related to myocardial infarction. Subdivision of patients with chronic obstructive pulmonary disease into groups with definite anatomic right ventricular hypertrophy, a clinical diagnosis of cor pulmonale, or with chronic hypoxemia failed to show any difference in the percentage of myocardial fibrosis of the ventricles among these groups. Increased fibrosis of the right or left ventricle in patients with chronic obstructive pulmonary disease, therefore, is not related to the degree of myocardial hypertrophy pathologically, the hypoxemic state, or clinical heart failure, but to ischemic heart disease with myocardial infarction.

Adult↗

PubMed1982

Correlation of left ventricular wall motion abnormalities with ventricular arrhythmias in patients with coronary artery disease.

We studied 71 patients with 12-hour Holter monitoring to determine if the incidence and complexity of ventricular arrhythmias in symptomatic coronary artery disease patients were related to the extent of left ventricular dysfunction. Their average age was 51 years, and each had cardiac catheterization within 3 months of study. Thirty-six patients had left ventricular aneurysms, 10 had normal left ventricular angiograms and 25 had left ventricular hypokinesis or akinesis without dyskinesis. The patients with aneurysms had significantly more heart failure, prior infarction, cardiomegaly and impaired ejection fractions. The mean premature ventricular contractions per hour for the aneurysm patients was 34 +/- 52, 3 +/- 5 for those with normal left ventricles, and 11 +/- 24 in the remainder. Complex premature ventricular contraction were noted in 50% of the aneurysm patients, in 10% of the patients with normal left ventricles and in 23% of the patients with hypokinesis or akinesis. Ventricular arrhythmias increase with greater left ventricular wall motion abnormality in patients with symptomatic coronary artery disease.

Adult↗

PubMed1981

Ventricular arrhythmia before and after aorto-coronary bypass surgery.

The influence of aorto-coronary bypass surgery (ACBS) on ventricular arrhythmia was examined in 57 patients. Six-hour Holter monitoring was done on the day prior to and 3 mth after ACBS. None of the patients were on any antiarrhythmic drugs during these recordings. Ventricular arrhythmia was classified into three groups: Group I (45 patients) had an average of less than 10 premature ventricular contractions (PVCs) per hour, Group II (7 patients), 11-30 PVCs per hour and Group III (5 patients), greater than 30 PVCs per hour. There was no significant change in the number of patients in each group after ACBS. Complex PVCs were present in 8 patients preoperatively and in 9 patients after ACBS. The number of diseased vessels and the extent of left ventricular wall motion abnormality noted preoperatively, had no effect on ventricular arrhythmia following surgery. These data show that ACBS, when performed to relieve angina, does not have a significant effect on the prevalence of PVCs and does not prevent or reduce the occurrence of complex PVCs.

Adult↗

PubMed1981

Systolic time intervals in the experimental animal with aortic outflow obstruction. Effect of digoxin.

This study shows significant changes occurring in systolic time intervals in an experimental animal model of aortic outflow obstruction with cardiac hypertrophy. The left ventricular ejection time is markedly prolonged and the preejection period/left ventricular ejection time ratio shortened. These changes are in the opposite direction of those usually observed with left ventricular dysfunction in man but similar to those described in man with aortic stenosis. Furthermore, the changes observed in systolic time intervals after digoxin in this experimental model are not comparable to those reported in man with normal or abnormal left ventricular function. Hence, the use of systolic time intervals, including digitalis effect, to evaluate the functional state of the left ventricle in aortic outflow obstruction are probably unreliable.

Animals↗

PubMed1980

The long-term suppression of ventricular arrhythmia by oral acebutolol in patients with coronary artery disease.

The short-term efficacy of oral acebutolol was evaluated in 20 patients with coronary artery disease and frequent premature ventricular contractions (PVCs) by serial 24-hour Holter monitoring before and while the patients were receiving an average daily dose of 1,100 mg. of acebutolol for four weeks. Fifty-five percent of the 20 patients showed a greater than 70% PVC reduction from baseline values. The only serious side effect during short-term therapy was mild, reversible cardiac decompensation in one patient. The long-term safety and continued efficacy of acebutolol was then evaluated over the next 11 months in nine of the 11 patients showing greater than 70% PVC reduction at four weeks. Two-thirds of these nine patients continued to show greater than 80% PVC reduction from baseline values at 12 months. One patient developed alopecia during long-term therapy. The majority of patients not responding well to acebutolol at four weeks had an actual increase in PVCs on acebutolol therapy. We conclude that acebutolol produces long-term, effective reduction in PVCs without serious toxicity in the majority of patients with ventricular ectopy. However, this drug appears to either produce an excellent response or no response with regard to PVC control in most instances.

Acebutolol↗

PubMed1980

Digoxin-quinidine interaction. Changes in canine tissue concentration from steady state with quinidine.

Tissue concentrations of tritiated digoxin inthe dog are altered by simultaneous administration of quinidine. Serum levels rise as tissue concentration decreases significantly in all tissue except brain tissue, where an increase of 51 percent is noted over that of the control digitalized state. The digitalis toxicity associated with digoxin-quinidine interaction appears to be associated with rising brain levels of digoxin and falling levels in the myocardium. These findings suggest a neurally mediated form of toxicity with this interaction related to a change in the space of distribution. The question of possible loss of inotropic effect associated with diminished myocardial digoxin concentration requires further study.

Animals↗

PubMed1979

The reliability of coronary angiogram interpretation: an angiographic-pathologic correlation with a comparison of radiographic views.

This prospective study correlates premortem coronary angiographic interpretation with pathologic findings including the use of postmortem coronary angiograms. The reliability of a single radiographic view, left anterior oblique or right anterior oblique, or combined views (left anterior oblique plus right anterior oblique) was examined. The most reliable interpretation, the combined view, has a specificity of 93 per cent, but sensitivity is less at 61 per cent. Using a single view enhances diagnosis (sensitivity), but it leads to overestimation more frequently (decreased specificity). Proximal segments of the coronary arteries are prone to a significant per cent of false positive readings. The most accurate assessment of the anterior descending coronary artery system occurs with the use of the right anterior oblique with multiple views. Less routine use of the left anterior oblique view with increased use of the hemiaxial view is suggested for the angiography of the left coronary artery. Initial cusp injections of the right coronary artery may avoid a high per cent of false positive readings in the proximal segment.

Angiography↗

PubMed1979

Evaluation of warning arrhythmias before paroxysmal ventricular tachycardia during acute myocardial infarction in man.

In order to determine the relationship of paroxysmal ventricular tachycardia (PVT) to any antecedent (premonitory) ventricular arrhythmias during the early phases of acute myocardial infarctions, 24-hour Holter monitoring was begun on 52 male patients an average of 12.6 hours after the onset of prolonged chest pain that was documented as acute infraction. Twenty-four patients had PVT and 28 did not. We analyzed in detail the incidence of frequency of premature ventricular complexes (PVCs), prematurity and pairing during the 10 minutes immediately preceding PVT from a continuous 10-minute rhythm strip. There was no positive correlation between PVT and the number or complexity of PVCs in the 10 minutes immediately before ventricular tachycardia. These findings suggest that there is no consistent pattern or frequency of ventricular arrhythmia that could be identified as premonitory for PVT during the immediate pre-PVT period, even during the acute phase of myocardial infarction in man.

Acute Disease↗

PubMed1978

Coronary angiogram interpretation. Interobserver variability.

Clinicopathological correlation of premortem coronary angiograms and postmortem data was performed to determine the degree of interobserver variability in the clinical interpretation of coronary angiograms using the pathological findings as the standard of accuracy. Comparison of the independent interpretations of the antemortem coronary angiograms by three cardiologists showed no substantial difference in overall diagnostic accuracy among the three observers. In the majority of instances where a substantial angiographic lesion was found on coronary angiography, it was verified pathologically. In false-positive or false-negative interpretations, a majority opinion was accurate when compared with a pathological lesion in 50% of the instances. Despite the fact that coronary angiography is an excellent diagnostic tool, there remain limitations of the accuracy of interpretation not solved by a majority opinion.

Angiography↗

PubMed1978

The relationship of paroxysmal ventricular tachycardia complicating the acute phase and ventricular arrhythmia during the late hospital phase of myocardial infarction to long-term survival.

The long-term prognosis of paroxysmal ventricular tachycardia (PVT) complicating acute myocardial infarction remains unevaluated. Significant ventricular arrhythmia in the patient after infarction is said to carry a poor prognosis with regard to survival. To evaluate these two important aspects of myocardial infarction in man, 56 patients with documented myocardial infarction had Holter monitoring performed during the initial 24 hours and prior to hospital discharge. In 38 of the 45 survivors, Holter monitoring was repeated an average of 19 months after infarction. There were eight cardiac deaths during follow-up. Data analysis revealed that of 18 patients with PVT during the acute phase, one died during follow-up and 17 survived long-term. Even though the incidence of complex PVCs prior to hospital discharge and at long-term follow-up was higher in patients with PVT during the acute phase than in those without PVT, survival appeared unaffected. Thus, PVT during the acute phase of myocardial infarction and complex PVCs at the time of hospital discharge are not incompatible with long-term survival.

Acute Disease↗

PubMed1978

Ventricular arrhythmias in chronic stable angina pectoris with surgical or medical treatment.

Since both propranolol therapy and saphenous-vein bypass surgery have become accepted treatments for patients with symptomatic coronary-artery disease, it is important to determine if either influences the prevalence of ventricular arrhythmias in these patients. Six-hour dynamic electrocardiography was done on 130 patients with chronic stable angina pectoris at least 1 year after being randomized to surgical or medical therapy. All surgical patients had saphenous-vein grafting; 90% of the medical patients received propranolol. Data analysis showed that even though the overall prevalence of premature ventricular contractions was no different in medical and surgical patients, the prevalence of complex premature ventricular contractions was significantly higher in surgically treated patients not receiving propranolol than in propranolol-treated medical patients (p less than 0.05). However, the survival rate was no different in either group, and the quality of life in the surgical patients remained superior.

Adult↗