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Biomedical subjects

R C Curry

Publications and source records attributed to R C Curry.

49 records · Page 3Linked to original sources
PubMed1979

Similarities of ergonovine-induced and spontaneous attacks of variant angina.

Ergonovine has been shown to provoke attacks of variant angina, but a question remains whether spontaneous and ergonovine-induced attacks of variant angina are similar. Seven patients with variant angina undergoing cardiac catheterization were studied during transient episodes of spontaneous and ergonovine-induced rest angina with ST-segment elevation. Clinical, electrocardiographic, left ventricular hemodynamic and coronary angiographic observations were made before and repeated after ergonovine (0.05-0.2 mg I.V.). The character and duration of chest pain were similar during both spontaneous and ergonovine-induced episodes. ST-segment elevation (greater than 1 mm) was present inferiorly in three patients, anteriorly in three patients, and both inferiorly and anteriorly in one patient during both episodes. Mean heart rate and systolic arterial pressure changed little, while left ventricular end-diastolic pressure increased significantly during spontaneous or ergonovine-induced attacks. We observed subtotal or total dynamic obstruction in the left anterior descending (three patients), right coronary arteries (three patients) and both arteries in one patient during both attacks. Thus, in selected patients ergonovine-induced attacks of variant angina were remarkably similar to spontaneous episodes.

Adult↗
PubMed1979

Aortic input impedance during nitroprusside infusion. A reconsideration of afterload reduction and beneficial action.

Beneficial effects of nitroprusside infusion in heart failure are purportedly a result of decreased afterload through "impedance" reduction. To study the effect of nitroprusside on vascular factors that determine the total load opposing left ventricular ejection, the total aortic input impedance spectrum was examined in 12 patients with heart failure (cardiac index <2.0 liters/min per m(2) and left ventricular end diastolic pressure >20 mm Hg). This input impedance spectrum expresses both mean flow (resistance) and pulsatile flow (compliance and wave reflections) components of vascular load. Aortic root blood flow velocity and pressure were recorded continuously with a catheter-tip electromagnetic velocity probe in addition to left ventricular pressure. Small doses of nitroprusside (9-19 mug/min) altered the total aortic input impedance spectrum as significant (P < 0.05) reductions in both mean and pulsatile components were observed within 60-90 s. With these acute changes in vascular load, left ventricular end diastolic pressure declined (44%) and stroke volume increased (20%, both P < 0.05). Larger nitroprusside doses (20-38 mug/min) caused additional alteration in the aortic input impedance spectrum with further reduction in left ventricular end diastolic pressure and increase in stroke volume but no additional changes in the impedance spectrum or stroke volume occurred with 39-77 mug/min. Improved ventricular function persisted when aortic pressure was restored to control values with simultaneous phenylephrine infusion in three patients. These data indicate that nitroprusside acutely alters both the mean and pulsatile components of vascular load to effect improvement in ventricular function in patients with heart failure. The evidence presented suggests that it may be possible to reduce vascular load and improve ventricular function independent of aortic pressure reduction.

Adult↗
PubMed1978

Ergonovine testing for coronary artery spasm in patients with angiographic mitral valve prolapse.

Coronary artery spasm (CAS) has been postulated to be a pathophysiologic mechanism in the production of ischemic-like chest pain and ECG changes in patients with idiopathic mitral valve prolapse syndrome. To evaluate the possible role of symptomatic CAS evoked by ergonovine maleate, this agent was administered (0.05 to 0.4 mg IV) to 24 patients with chest pain and mitral valve prolapse who had no significant (less than 50%) coronary artery obstruction. Symptoms, ECG and blood pressure changes were monitored in all patients following ergonovine administration. No significant changes were observed in heart rate, systolic blood pressure, or double product. Six patients developed their typical chest pain. In two of these six with chest pain, ST segment shift greater than 1 mm were seen. Post-ergonovine left ventricular end-diastolic pressure (LVEDP) and coronary angiographic changes were also studied in subgroup of 12 of these patients, including five of the six chest pain responders. In the five chest pain responders, pain was associated with a significant rise in LVEDP, whereas no significant change occurred in those patients not experiencing chest pain (p less than 0.01). Chest pain was also associated with significant CAS (greater than 50% lumen reduction) in two patients, each with ST segment shifts greater than 1 mm. In summary, ergonovine stimulation failed to evoke symptoms, ECG or blood pressure changes in three quarters of mitral valve prolapse patients studied. Six patients developed chest pain. Chest pain was assoicated with ECG changes characteristic of CAS in two of these patients, each with angiographic CAS. Thus, symptomatic CAS induced by ergonovine was absent in the majority of these 24 patients with idiopathic mitral valve prolapse syndrome.

Adult↗
PubMed1978

Propranolol therapy during pregnancy in a patient with idiopathic hypertrophic subaortic stenosis: is it safe?

A case is presented of a low birth weight infant born prematurely with depressed respiration, sinus bradycardia, and hypoglycemia associated with maternal propranolol therapy during pregnancy and up until labor and delivery. The need for caution in the casual use of propranolol during pregnancy in an asymptomatic patient with IHSS and the potential fetal complications are emphasized.

Adult↗
PubMed1978

Myocardial infarction and normal coronary arteries.

This case report adds evidence against the role of coronary artery spasm as a mechanism in the syndrome of acute myocardial infacrtion in the presence of normal coronary arteries. Myocarditis, the suggested cause of this patient's symptoms, has been frequently overlooked as a cause for this syndrome.

Acute Disease↗
PubMed1978

Pulsatile flow characteristics of aortic valve porcine heterografts in man.

Pulsatile flow characteristics in the ascending aorta were examined in 14 patients 12 months after aortic valve replacement with the glutaraldehyde-fixed porcine aortic heterograft. Analysis of the velocity signals permitted measurement of peak velocity, maximal acceleration, stroke volume, and ejection time in addition to the standard measurement of systolic aortic valvar gradient. Angiographic techniques permitted visualization of a pattern of blood flow in the ascending aorta. Valvar aortic gradients were minimal, and, when the phasic ascending aortic blood flow velocity parameters were compared to those in a group of eight patients with normal aortic valves, these characteristics of flow were nearly indistinguishable. This remarkable similarity to the flow characteristics of normal valves may be important to long-term performance of a prosthetic aortic valve. Our results suggest that the glutaraldehyde-fixed porcine heterograft warrants serious consideration when selecting a substitute aortic valve for man.

Animals↗
PubMed1977

Detection of a temporary cardiac pacing catheter in the left ventricle by chest X-ray.

This is the first reported case of detection by chest radiograph of a temporary cardiac pacing catheter inadvertently placed in the left ventricle. The unusual catheter position seen in the first chest radiograph was confirmed by a second film following reinsertion of the catheter into the right ventricle. The importance of roentgenographic confirmation of temporary cardiac pacing catheters, especially those inserted without fluoroscopy, is reemphasized.

Adult↗