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Biomedical subjects

A N DeMaria

Publications and source records attributed to A N DeMaria.

At least 217 records · Page 12Linked to original sources
PubMed1978

Hydralazine-induced tachycardia and sodium retention in heart failure. Hemodynamic and symptomatic correction by prazosin therapy.

Severe tachycardia, ventricular ectopy, and sodium retention manifested by hemodynamic deterioration developed with hydralazine hydrochloride therapy in chronic coronary heart disease with congestive failure refractory to digitalis, diuretics, and nitrates. Coronary care unit admission with Swan-Ganz catheterization corrected hemodynamics by sodium nitroprusside treatment after hydralazine withdrawal. Satisfactory cardiac performance with oral long-acting nitrates were unsuccessful. However, the new oral vasocilator, prazosin hydrochloride, achieved considerable hemodynamic benefit by greatly reducing elevated left ventricular filling pressure and increasing severely depressed cardiac index to normal, accompanied by striking symptomatic improvement. Furthermore, long-term enhancement of cardiac dynamics and salutary functional status was maintained by ambulatory oral prazosin therapy for several months. This experience demonstrates the favorable alternative of prazosin nitroprusside-like actions over hydralazine-nitrate therapy in heart failure therapy and emphasizes prazosin's utility when untoward side effects to hydralazine develop.

Aged↗
PubMed1977

Improved longevity due to reduction of sudden death by aortocoronary bypass in coronary atherosclerosis.

To evaluate the efficacy of coronary bypass surgery in reduction of sudden death, the prognosis of 286 similar patients with multivessel coronary stenosis was studied prospectively and the results of medical therapy (Group I, 114 patients) were compared with those of surgical therapy (Group II, 172 patients) after cardiac catheterization and coronary arteriography. During 39 months' evaluation of both groups, mortality from congestive heart failure and noncardiac causes did not differ (Group I, 14 percent; Group II, 8 percent) (P greater than 0.05). Sudden was evaluated in the remaining 217 patients (Group I, 96; Group II, 121 patients) who were matched for age (Group I, 52 years; Group II, 51 years); duration of overt coronary disease (Group I, 3.8 years; Group II, 4.0 years); angina pectoris (Group I, 83 percent; Group II, 95 percent); prior myocardial infarction (Group I, 77 percent; Group II, 74 percent); and congestive heart failure (Group I, 30 percent; Group II, 23 percent) (all P greater than 0.05). In addition, the prevalence of coronary risk factors was the same (P greater than 0.05) in both groups (hypertension, cigarette smoking, diabetes mellitus, lipid abnormalities and family history of coronary disease). Importantly, arteriography and catheterization established a similar extent and location of major coronary arterial stenoses and of ventricular dysfunction; two vessel disease (Group I, 32 percent; Group II, 33 percent) and three vessel disease (Group I, 68 percent; Group II, 67 percent); left ventricular end-diastolic pressure (Group I, 13; Group II, 14 mm Hg);cardiac index (Group I, 2.85; Group II, 2.91 liters/min per m2); and coronary collateral vessels (Group I, 58 percent; Group II, 61 percent) (all P greater than 0.05). Fifty-six percent of patients in Group II had multiple bypass grafts and a late patency rate (average 21 months) of 87 percent of one or more grafts. During subsequent prospective evaluation of over 3 years, bypass surgery provided greater symptomatic benefit of improved functional capacity (Group I, 12 percent; Group II, 69 percent) (P less than 0.05) and complete anginal relief (Group I, 30 percent; Group II, 60 percent) (P less than 0.05). Moreover, bypass surgery was associated with marked reduction in sudden death (Group I, 24 percent; Group II, 6 percent) (P less than 0.05). Thus, in patients with multivessel coronary disease carefully matched for clinical factors, hemodynamics, atherogenic precursors and coronary pathoanatomy, effective aortocoronary bypass surgery appeared to prolong survival by decreasing the incidence of sudden death, possibly by a decrease of unexpected fatal arrhythmias.

Cardiac Catheterization↗
PubMed1977

Echocardiographic identification of the mitral valve prolapse syndrome.

The data presented herein would indicate that mitral valve prolapse may be represented by a variable spectrum of abnormalities on the echocardiogram. Utilizing all the abnormalities described, echographic evidence of mitral valve prolapse may be detected in most patients with this disorder. However, evidence of mitral valve prolapse may also be observed in a large contingent of asymptomatic patients without other clinical manifestations of cardiac disease. The biologic significance of these echographic abnormalities remains uncertain and constitutes an important area for future investigation.

Cineangiography↗
PubMed1977

Multifactor evaluation of the determinants of ischemic electrocardiographic response to maximal treadmill testing in coronary disease.

Despite widespread use of treadmill stress in the detection of coronary disease, detailed information relating the important features of coronary pathoanatomy to the ischemic response noted on the electrocardiogram is lacking. Accordingly, 91 consecutive patients undergoing graded maximal exercise tests (MEXT) who were found to have clinical stenosis (larger than or equal to 75 per cent luminal narrowing) of at least one of the three major coronary arteries on coronary arteriography were evaluated. Positive MEXT was defined as larger than or equal to 0.1 mV horizontal or downsloping S-T segment depression larger than or equal to 0.08 second beyond J point. Over-all sensitivity of positive MEXT was 59 of 91 (65 per cent) patients; 11 of 26 (42 per cent) with single vessel stenosis, 20 of 30 (66 per cent) with two vessel disease and 28 of 35 (80 per cent) with three vessel disease. In patients with two vessel disease, the frequency (p less than 0.05) of positive MEXT was greater in those with (15 of 21;71 per cent) than in those without (five of nine; 55 per cent) stenosis of the left anterior descending artery. Concerning the site of intravessel stenosis, the frequency of positive MEXT was greater (p less than 0.05) with stenosis proximal to the left anterior descending artery in patients with one vessel disease. Quantification of total numbers of intra- and intervessel stenoses revealed 2.7 stenoses in the 59 patients with positive MEXT in contrast (p less than 0.01) to 1.9 in 32 patients with negative MEXT. Similarly, graded luminal narrowing index of severity of total stenoses per patient was 9.9 in those with positive MEXT compared (p less than 0.01) to 6.1 in those with negative MEXT. The poststenotic myocardial perfusion index, estimated by graded distal vessel opacification per major vessel disease, was only 1.5 in those with positive MEXT contrasted (p less than 0.01) to 2.4 in those with negative MEXT. These data indicate that sensitivity of positive MEXT in patients with coronary disease is most closely determined by the number of major coronary vessels involved, the total number of major vessels stenosed, the severity of total stenoses and poststenotic distal vessel perfusion. Less important factors are the precise site of intravessesl stenosis and the specific major coronary artery involved, although stenosis proximal to the left anterior descending artery favored positive MEXT. Unimportant variables were the quality of collateral vessels, ventricular function and prior inferior infarction. Angina occurred more frequently in those with positive MEXT, and marked degree of positive MEXT indicated stenosis proximal to the left anterior descending artery.

Adult↗
PubMed1977

Clinical evaluation of the enhancement of vagal tone in acute myocardial infarction by edrophonium hydrochloride: effects on ventricular arrhythmias, His bundle electrography, and left ventricular function.

Enhanced electrical stability of acutely ischemic myocardium with vagal stimulation and acetylcholinesterase inhibition has been demonstrated experimentally. To extend these findings clinically, within 24 hours of acute myocardial infarction, 11 patients underwent continuous 10 hour Holter monitoring: 2.5 hour control before and after 5 hour constant edrophonium infusion (0.25 to 2.00 mg./minute). Continuous infusion of the agent lowered heart rate 92 to 78 b.p.m. (p less than 0.01). Although mean total ventricular extrasystoles (PVC's) per 5 hours per patient (131) and PVC's per 1,000 beats (4.7) were unchanged (p greater than 0.05), potentially lethal tachyarrhythmias (malignant PVC's: multifocal, R on T, paried, greater than 5 per minute or ventricular tachycardia) were terminated in six of 10 patients by edrophonium. However, serious ventricular arrhythmias continued in three patients and appeared in four despite the agent. Ventricular fibrillation did not occur during the 10 hour period of study. In addition, the patients were evaluated hemodynamically and by His bundle electrograms before and after a 10 mg. bolus of edrophonium prior to the 10 hour constant infusion: heart rate declined (88 to 72 b.p.m., p less than 0.01), while mean arterial pressure (98 mm. Hg), left ventricular filling pressure (14 mm. Hg), cardiac index (2.4 L. per minute per square meter), and stroke work index (36 Gm.m./M.2) were unchanged (p greater than 0.05). The edrophonium bolus prolonged the A-H interval (117 to 135 msec., p less than 0.01) while the H-Q interval was unaltered (48 msec; p greater than 0.05). It is concluded that increased vagal tone with edrophonium did not reduce the over-all presence of premature ventricular contractions in the entire study group; however, the malignant nature of PVCs and ventricular tachycardia appeared to be lessened by the parasympathomimetic agent in certain patients. In addition, no adverse hemodynamic or intraventricular conduction effects were produced by edrophonium administration.

Acetylcholinesterase↗
PubMed1977

Combined dopamine and nitroprusside therapy in congestive heart failure. Greater augmentation of cardiac performance by addition of inotropic stimulation to afterload reduction.

The hemodynamic benefits of combining administration of dopamine with nitroprusside (NP) were evaluated in nine patients with chronic congestive heart failure due to ischemic, idiopathic myocardial or valvular cardiac disease. NP alone (68 microng/min) produced decline in left ventricular end-diastolic pressure (LVEDP) from 25.4 to 14.1 mm Hg (p less than 0.01) but modest increase in cardiac index (CI) from 2.41 to 3.02 L/min/m2 (P less than 0.05). Dopamine alone (6 microng/kg/min) caused an elevation of CI to 3.36 (P less than 0.01) but without decrease of LVEDP. Simultaneous infusion of the two agents resulted in favorable alterations in both hemodynamic variables: LVEDP decreased to 15.7 (P less than 0.01) and CI increased to 3.52 (P less than 0.01). It is concluded that dopamine substantially enhances the effectiveness of nitroprusside therapy in congestive heart failure by providing concomitantly the principal beneficial actions of the vasodilator and dopamine used separately. Thus combined dopamine with NP treatment considerably raises low CI while markedly reducing elevated LVEDP and provides a potentially efficacious pharmacologic modality for the treatment of severe congestive heart failure due to left ventricular dysfunction.

Adult↗
PubMed1977

Efficacy of ambulatory systemic vasodilator therapy with oral prazosin in chronic refractory heart failure. Concomitant relief of pulmonary congestion and elevation of pump output demonstrated by improvements in symptomatology, exercise tolerance, hemodynamics and echocardiography.

The long-term efficacy of the new oral vasodilator, prazosin (PZ), was evaluated in nine patients with refractory heart failure due to chronic coronary heart disease. Ventricular function was assessed by cardiac catheterization, echocardiography, and treadmill testing; symptomatic evaluation was carried out for two to four months. One hour following 2-7 mg PZ, control left ventricular filling pressure was reduced (32 to 18 mm Hg, P less than 0.001) and cardiac index was elevated (1.95 to 2.89 L/min/m2, P less than 0.001) for a 6-hour period. After two weeks of PZ 2 to 7 mg four times daily, echographic end-diastolic dimension fell (5.7 to 5.4 cm, P less than 0.001) while shortening fraction increased (27.6 to 30.2%, P less than 0.005). Treadmill exercise duration increased from 209 to 317 seconds (P less than 0.001). Symptoms diminished throughout the duration of follow-up (mean 94 days) with improvement in NYHA functional class (3.7 to 2.2, P less than 0.001). Thus, prazosin possesses sustained nitroprusside-like balanced dilator actions on the systemic arterial and venous systems and is effective in the ambulatory management of chronic severe heart failure.

Administration, Oral↗
PubMed1977

Effects of digitalis on the exercise electrocardiogram in normal adult subjects.

Controversy continues regarding the effects of administration of digitalis upon the exercise electrocardiogram. Thus, maximal treadmill exercise tests were performed before and two weeks after administration of 0.25 mg of digoxin daily in 15 normal subjects (documented by cardiac catheterization and coronary arteriographic studies). Administration of digitalis induced abnormal findings on exercise tests in all 14 subjects with serum levels of digoxin greater than or equal to 0.5 ng/ml; however, at workloads greater than 75 to 90 percent of maximal predicted heart rate, the changes in the ST segment reverted to a normal configuration in all subjects, thereby providing differentiation of digitalis-induced ST-segment alterations from those due to myocardial ischemia at maximal treadmill stress.

Adult↗
PubMed1976

Afterload reduction therapy with nitroprusside in severe aortic regurgitation: improved cardiac performance and reduced regurgitant volume.

To assess the hemodynamic effects of afterload reduction in severe aortic regurgitation, nitroprusside was infused at cardiac catheterization in 12 patients with aortic regurgitation. Cardiac hemodynamics, angiographic variables and regurgitant volumes were quantified during control periods, and nitroprusside was infused to reduce systemic systolic pressure to 110 to 125 mm Hg. The following were reduced by the drug: systolic arterial pressure (from 154 +/- 6.4 to 115 +/- 2.3 mm Hg, P less than 0.001); left ventricular end-diastolic pressure (from 23 +/- 2.2 to 11 +/- 1.0 mm Hg, P less than 0.001); systemic vascular resistance (from 1,782 +/- 133 to 1,148 +/- 94 dynes sec cm-5, P less than 0.001); left ventricular end-diastolic volume (from 242 +/- 25 to 196 +/- 19 ml, P less than 0.001); aortic regurgitant fraction (from 0.53 +/- 0.05 to 0.44 +/- 0.06, P less than 0.01); and aortic regurgitant minute volume (from 5.5 +/- 0.10 to 4.3 +/- 0.09 liters/min, P less than 0.01). Effective cardiac index increased (from 2.49 +/- 0.19 to 3.10 +/- 0.24 liters/min per m2, P less than 0.01), and left ventricular ejection fraction rose (from 0.55 +/- 0.03 to 0.61 +/- 0.03, P less than 0.005). These data indicate that afterload reduction with nitroprusside in severe aortic regurgitation improves cardiac performance, greatly decreases left ventricular preload and reduces aortic regurgitant volume. Thus, nitroprusside therapy has special value in severe aortic regurgitation that is of particular benefit in critical clinical conditions.

Aged↗
PubMed1976

Efficacy of cardioselective beta adrenergic blockade with intravenously administered tolamolol in the treatment of cardiac arrhythmias.

The efficacy of tolamolol, a cardioselective beta adrenergic blocking agent, was evaluated in the treatment of cardiac arrhythmias in 27 patients. Nineteen patients had supraventricular arrhythmias and eight had ventricular arrhythmias. Evaluation was by doulbe-blind randomized trial in 23 patients. Tolamolol was effective in reducing ventricular rate in 17 (85 percent) of 19 patients with supraventricular arrhythmias and resulted in conversion to sinus rhythm in 2 of the 17. The mean ventricular rate in 17 patients decreased from 135 to 102/min 10 minutes after initiation of administration of tolamolol and gradually decreased further to 93/min after 60 minutes. Reduction in ventricular rate was sustained for 2 hours of monitoring undergone by all patients and for 4 and 6 hours monitoring in two subgroups. Among the eight patients with ventricular ectopic beats, tolamolol reduced their frequency in four patients and had no effect in four. Six patients had chronic obstructive pulmonary disease and experienced no adverse clinical effects on respiratory function in association with administration to tolamolol. Untoward effects occurred in 10 patients, including hypotension in 3, 1 of whom required vasopressor therapy. Other side effects were sedation, nausea, dyspnea and warmth in the chest, all of which were mild and transient, requiring no treatment. Cardioselective beta adrenergic blockade with tolamolol was highly effective in controlling ventricular rate in supraventricular arrhythmias and reduced the frequency of ventricular ectopic beats in half of the small group of patients with this arrhythmia. It is particularly applicable in patients with obstructive pulmonary disease in whom cardiac beta adrenergic blockade is indicated. Hypotension is an important potential side effect.

Adrenergic beta-Antagonists↗
PubMed1976

Mitral valve early diastolic closing velocity in the echocardiogram: relation to sequential diastolic flow and ventricular compliance.

Uncertainty exists regarding the determinants of mitral valve early diastolic closing velocity (E-F slope) in the echocardiogram. Accordingly, the mitral E-F slope, sequential atrioventricular flow in each third of diastole in the cineangiogram and an index of ventricular compliance (delta volume/delta pressure normalized by end-diastolic volume) were obtained in 10 normal subjects, 10 patients with coronary artery disease and marked dyssynergy and 9 patients with hypertrophic cardiomyopathy. The E-F slope of 103 +/- 20 mm/sec (mean +/- standard deviation) in normal subjects was greatly reduced in patients with coronary artery disease and hypertrophic cardiomyopathy (54 +/- 22 and 27 +/- 16 mm/sec, respectively, P less than 0.001). Transmitral flow of 52 +/- 25 cc during the initial third of diastole in normal subjects represented 48 +/- 10 percent of total flow and was diminished in patients with coronary artery disease and hypertrophic cardiomyopathy: 23 +/- 16 cc (25 +/- 24 percent) and 24 +/- 20 cc (20 +/- 11 percent), respectively (both P less than 0.001). The ventricular compliance index in normal subjects of 0.064 +/- 0.02 was also decreased identically in patients with coronary artery disease and hypertrophic cardiomyopathy: 0.029 (both P less than 0.001). The E-F slope was correlated with transmitral flow during the first third of diastole (r = 0.87) but was decreased to a slightly greater extent for any given reduction in flow in patients with hypertrophic cardiomyopathy than in patients with coronary artery disease. Although the E-F slope could not be related to compliance in individual patients, patients with an E-F slope of less than 75 mm/sec nearly always had diminished compliance. Thus, mitral E-F slope is primarily related to transmitral flow in the initial third of diastole. Reduced ventricular diastolic compliance usually results in diminished flow, and thus a decreased E-F slope, in patients with coronary artery disease or hypertrophic cardiomyopathy. The greater reduction in E-F slope for any decrement of flow in hypertrophic cardiomyopathy than in coronary disease may be due either to interference with vortex streaming or to alterations in the relation of the papillary muscles to the mitral valve induced by altered ventricular geometry; the finding indicates that factors in addition to flow may influence the E-F slope.

Adult↗