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Biomedical subjects

R Gorlin

Publications and source records attributed to R Gorlin.

At least 109 records · Page 6Linked to original sources
PubMed1980

Silent ST segment deviations and extent of coronary artery disease.

Fifty patients who underwent coronary and left ventricular angiography for suspected coronary artery disease (CAD) had ambulatory ECG monitoring at a time remote from that of catheterization. After correcting for positional ST segment variation on ambulatory ECG, the amount of time that ST segments deviated more than 1 mm. from baseline without corresponding angina was determined, and these results were correlated with results of angiography. Silent ST segment deviations were seen in patients without significant CAD in 2.2% of observations, but increased significantly with extent of coronary artery disease (2.9%, 8.2%, and 10.1% of observations in the one-, two-, and three-vessel disease groups, respectively). This relationship was independent of ventricular function, resting ECG, and previous symptoms. It is concluded that silent ST segment deviations on ambulatory ECG reflect the presence and severity of coronary artery disease.

Adult↗
PubMed1980

Hemodynamic correlates of late diastolic posterior motion of the aortic root.

Motion of the posterior aortic root on echocardiography is related to left atrial volume changes. Early diastolic posterior motion of the aortic root reflects both LA emptying and filling and has been measured as the atrial emptying index. To study late diastolic motion of the aortic root, we measured the slope of posterior motion of the aortic root after left atrial systole (following the P wave of the ECG) in 25 subjects without heart disease (Group 1), in 15 patients with left ventricular hypertrophy due to pressure overload (Group 3) with mitral stenosis. The aortic root slope measured (mean +/- SEM) 58.0 +/- 1.9 mm./sec. in Group 1, 50.6 +/- 4.5 mm./sec. in Group 2 (NS vs 1) and 28.8 +/- 4.5 mm./sec. in Group 3, (p < 0.01 vs 1 or 2). In 16 patients (four in Group 1 and 12 in Group 2) studied at catheterization, an inverse correlation ( r = -0.74, p < 0.01) was found between the aortic root slope (over a range of 30 to 73 mm./sec.) and left ventricular late diastolic chamber stiffness measured with simultaneous left ventricular echo and high-fidelity pressure recordings. No correlation was found between this slope and either left atrial size, total aortic root excursion, left ventricular pressure pre "A" wave, height of the A wave, end-diastolic pressure, or the atrial contribution to left ventricular filling. Therefore, the aortic root slope in late diastole is decreased in mitral stenosis and in the absence of mitral stenosis, it appears to be related to late diastolic properties of the left ventricle.

Adult↗
PubMed1980

Use of the ambulatory ECG to diagnose coronary artery disease.

Forty-nine patients undergoing cardiac catheterization for suspected coronary artery disease (CAD) were monitored with a two-channel ambulatory ECG and were given maximal treadmill exercise tests when these were not contraindicated. The ambulatory ECG recordings were evaluated for the number of ST segment deviations after correction for positional changes, and the results were then compared with those of the exercise test and coronary angiography. Sensitivity and specificity of ambulatory ECG monitoring for ST segment deviations to detect CAD were 76% and 75% respectively while those of exercise testing were 78% and 63% respectively. Sixteen patients (33% of this series) had equivocal or contraindicated exercise tests and twelve of these patients were correctly classified as to the presence or absence of CAD by ambulatory ECG. ST segment deviations on ambulatory ECG were found in 93% of patients with three vessel, two vessel, or one vessel LAD disease, while exercise testing detected 74% of these patients. Ambulatory ECG is an effective non-invasive method to diagnose CAD and is complementary to excercise testing. It is of special value when the exercise test is equivocal or contraindicated.

Adult↗
PubMed1980

Superficial accessory pathway in the Wolff-Parkinson-White syndrome--electrophysiological, surgical and histologic demonstration.

A superficial accessory pathway was demonstrated by electrophysiologic techniques and surgical histopathology in 30-year-old male with Wolff-Parkinson-White syndrome, severe mitral valve disease and medically uncontrollable arrhythmias. In this patient, electrode catheter studies in the cardiac catheterization laboratory revealed antegrade and retrograde function of an accessory pathway between the anterior right atrium and the right ventricle. During surgery, electrophysiologic mapping confirmed the anterior location of this pathway. Blunt dissection in the fat pad of the A-V groove between the right atrium and ventricle revealed the accessory pathway which consisted of tissue strands superficial to the A-V ring. These were removed and on histological examination were composed of ordinary myocardial cells. Concomitant replacement of the patient's calcified stenotic and regurgitant mitral valve was carried out. Postoperatively, there was complete regression of the preexcitation and arrhythmias.

Adult↗
PubMed1980

Hemodynamic evaluation of hydralazine dosage in refractory heart failure.

Hemodynamic responses to different doses of hydralazine were evaluated in 18 patients with severe refractory resistant heart failure. There were no significant overall hemodynamic effects after 50 mg hydralazine. After 75 mg, CI increased slightly (+0.36 l/min/m2) with a 19% decrease in SVR. After 100 mg, there were substantial increases in CI (+0.60 l/min/m2) and decreases in SVR (31%) changes which were greater than those after 75 mg, but the decrease in MAP with 100 mg (-6.6 mm Hg) was of the same order as that after 75 mg (-5.0 mm Hg). LVFP and SWI improved significantly only with 100-mg doses. Seven patients in whom 100 mg hydralazine induced no hemodynamic effects all responded to single doses of 150 to 200 mg. The duration of action of hydralazine was longer (p less than 0.001) in patients with a CCr less than 35 ml/min (14.3 +/- 1.4 hr) than in patients with adequate renal function (7.9 +/- 0.5 hr). Thus, the dose and dosing interval of hydralazine needed to induce hemodynamic improvement in patients with severe heart failure are variable and require individualization.

Aged↗
PubMed1980

Coronary artery spasm and perioperative cardiac arrest.

There has been increasing interest in coronary artery spasm as etiopathogenic mechanism for various syndromes associated with myocardial ischemia. A case with documented organic coronary artery disease is presented, in which coronary artery spasm was the probable cause of intraoperative and early postoperative cardiac arrest. We recommend that coronary spasm be considered in the differential diagnosis of perioperative cardiac arrest.

Angina Pectoris, Variant↗
PubMed1979

Rebound hemodynamic events after the abrupt withdrawal of nitroprusside in patients with severe chronic heart failure.

We studied the hemodynamic events that followed abrupt withdrawal of nitroprusside in 20 patients with severe chronic heart failure. With nitroprusside, cardiac index increased from 1.96 to 2.87 liters per minute per square meter of body-surface area, but it decreased to 1.66 (P less than 0.001) after withdrawal of nitroprusside. Left ventricular filling pressure and systemic vascular resistance decreased from 23.9 to 15.3 mm Hg and from 1642 to 921 dyn.sec.cm-5, respectively, with nitroprusside, but increased to 30.4 mm Hg and 2109 dyn.sec.cm-5 (both P less than 0.001) upon its discontinuation. These rebound changes were maximal 10 to 30 minutes after nitroprusside withdrawal and returned to control levels one to three hours later. Although in 17 of 20 patients, these rebound changes caused no or minimal exacerbation of symptoms, pulmonary edema, which resolved in three patients. Activation of reflex vasoconstrictive forces during vasodilator therapy may explain these effects of withdrawal.

Adult↗
PubMed1979

Differences in hemodynamic effects of nitroprusside and prazosin in severe chronic congestive heart failure: evidence for a direct negative chronotropic effect of prazosin.

To compare the hemodynamic effects of prazosin and nitroprusside in patients with severe congestive heart failure, nine patients with heart failure refractory to conventional therapy received oral prazosin and intravenous nitroprusside administered so as to produce a similar decrease in left ventricular filling pressure in each patient. By this comparison, both drugs produced similar decreases in mean right atrial pressure, mean pulmonary arterial pressure and systemic and pulmonary vascular resistance. However, with nitroprusside, cardiac index increased more (+0.97 versus +0.73 liters/min per m2, P less than 0.01) and mean arterial pressure decreased less (-13.7 versus -18.3 mm Hg, P less than 0.05) than with prazosin. Both drugs produced similar changes in stroke volume index (+11.7 cc/beat per m2 with nitroprusside and +12.5 with prazosin) and stroke work index (+8.1 g-m/m2 with nitroprusside and +6.6 with prazosin). Therefore, the differences in the hemodynamic responses observed with the two agents were due to the significantly greater decrease in heart rate with prazosin (-8 beats/min) than with nitroprusside (-2 beats/min, P less than 0.05). These clinical data support experimental evidence suggesting that there is a significant negative chronotropic action of prazosin independent of its peripheral vascular effects.

Administration, Oral↗
PubMed1979

Sustained effect of orally administered isosorbide dinitrate on exercise performance of patients with angina pectoris.

The efficacy of oral isosorbide dinitrate was evaluated in nine hospitalized patients with chronic angina pectoris and positive maximal bicycle exercise tests. Patients were randomized double-blind to receive either 20 mg of isosorbide dinitrate or placebo on successive days after a control maximal upright bicycle exercise test. On each day hourly exercise tests were performed for 4 hours after drug administration to an end point of fatigue or angina pectoris. Mean systolic blood pressure 4 hours after the administration of isosorbide dinitrate was 25 mm Hg less than the control value (P less than 0.001). The values for resting heart rate and exercise-attained heart rate-blood pressure product were not significantly different from the values after placebo. The duration of exercise was prolonged (P less than 0.025) for at least 3 hours, and less ST depression (P less than 0.01) was observed up to 3 hours after the administration of isosorbide dinitrate compared with control values. The demonstration of sustained imporved exercise performance and previously described hemodynamic effects with the use of higher doses suggests that adequate blood levels of isosorbide dinitrate or mononitrate metabolites may be important for the efficacy of oral organic nitrates.

Administration, Oral↗
PubMed1977

Ventricular premature beats and anatomically defined coronary heart disease.

Ambulatory 24 hour electrocardiographic monitoring was performed in 124 patients before cardiac catheterization and coronary angiography. Ventricular premature beats were demonstrated in 83% of all patients. Ectopic activity persisted for at least 3 of the 24 hours in 75% of the 84 patients with coronary heart disease, 61% of 28 with other heart disease and in 24% of 12 normal subjects. The prevalence and grade of ventricular premature beats were increased in the 57 patients with multivessel disease compared with values in the 27 patients with one vessel disease (P less than 0.01). Findings in the latter group did not differ from those of normal subjects. The presence of elevated left ventricular end-diastolic pressure of asynergy was associated with increased ventricular ectopy. Of 15 patients having both asynergy and elevated left ventricular end=diastolic pressure (more than 19 mm Hg), 40% had paroxysms of ventricular tachycardia and 67% had coupled beats; these findings were present in 6 and 12%, respectively, of the 34 patients without asynergy or pressure abnormality (P less than 0.005). Repeat monitoring performed in 65 patients demonstrated greater reproducibility of advanced grades of ventricular premature beats among those with the most severe lesions. For the individual patient the prevalence and grade of ventricular ectopy may not always correlate with the severity of coronary artery disease or degree of left ventricular dysfunction.

Adult↗