Inhalation of amyl nitrite and the measurement of left ventricular outflow velocity: studies in normal, young adults.

Amyl nitrite inhalation is useful in the identification of patients with provocable left ventricular (LV) outflow tract obstruction. However, there are no prospective studies that assess the normal change in LV outflow velocity during this intervention. Eighteen normal subjects (mean age, 34+/-5 years; 9 men and 9 women) inhaled amyl nitrite during measurement of LV outflow velocity. Peak velocity increased from 109+/-16 cm/s to 144+/-24 cm/s (P<0.001). There were no significant gender differences in velocity measurements at baseline or at peak. Our study provides prospective data that may be useful when evaluating young adults for LV outflow tract obstruction with Doppler echocardiography during amyl nitrite inhalation.

Reproducibility and variability of the amount of tricuspid regurgitation with color Doppler echocardiography.

The measurement of right atrial area was variable between different observers; however, quantitation of tricuspid regurgitation with color Doppler is a reproducible method with an acceptable error of measurement.

Transcatheter embolization of an internal mammary artery bypass graft sidebranch causing coronary steal syndrome.

We describe a 66-yr-old man with angina after internal mammary artery-coronary bypass grafting due to coronary artery steal by a sidebranch of the mammary artery. Myocardial ischemia was successfully treated by transcatheter embolization of the sidebranch.

Impact of transesophageal echocardiography on the anticoagulation management of patients admitted with focal cerebral ischemia.

Transesophageal echocardiography (TEE) improves the diagnostic accuracy of transthoracic echocardiography in the identification of potential cardiac sources of embolus. However, there are few studies of the impact of TEE on the medical management of patients with focal cerebral ischemia. The records of 52 consecutive, hospitalized patients undergoing both TEE and transthoracic echocardiography for suspected cardiac source of embolus were reviewed to determine the influence of TEE on the decision to anticoagulate patients. Of 52 patients, 39 had focal cerebral ischemia (transient ischemic attack, n = 9; acute cerebral infarction, n = 30). In 4 of these 39 patients (10%), the TEE results changed the management of anticoagulation. In 19 of 39 patients (49%), the TEE results helped confirm anticoagulation decisions, and in 16 (41%), the results had no effect on anticoagulation decisions, because of overriding clinical information. Ten of the latter 16 patients had TEE evidence for a possible source of an embolus, but were not anticoagulated; 5 of these were poor candidates for long-term anticoagulation, and the others had right-to-left shunting across a patent foramen ovale or an interatrial septal aneurysm. Clinical variables (atrial fibrillation, TEE findings and pre-TEE anticoagulation status) were considered as possible predictors of post-TEE anticoagulation status using logistic regression analysis; the strongest predictor of post-TEE anticoagulation status was pre-TEE anticoagulation status (p < 0.0005). Despite the selection of patients presumed to receive maximal benefit from TEE, this study suggests that TEE findings are not predictive of subsequent anticoagulation management. However, TEE is at least confirmatory of anticoagulation decisions in most cases.

Use of echocardiography in detecting cardiac sources of embolus.

Up to 20% of all ischemic strokes are felt to be the result of emboli from the heart. High resolution transthoracic (TTE) and transesophageal (TEE) echocardiography have been the principal diagnostic tools for detecting associated cardiac abnormalities and for guiding medical and surgical approaches to these patients. In addition to identifying the precise location and morphological characteristics of intracardiac masses, echocardiography has improved our ability to predict embolic potential of these masses. Specific cardiac lesions that are predisposed to stroke and are readily identifiable by echocardiography include: cardiac thrombi, valvular vegetations, cardiac tumors, aortic atheroma, atrial septal aneurysm, and regional left ventricular wall abnormalities. Careful interrogation of patients with cerebrovascular accidents has identified a potential cardiac source of embolus in approximately 30%. This is largely due to the advent of TEE, which has provided much better assessment of posterior cardiac chambers including left atrium and left atrial appendage. Use of TEE in identifying a cardiac source of embolus is indicated in patients with stroke who are young, have no apparent cerebrovascular disease, or have recurrent embolic events. Echocardiography is an essential diagnostic tool in evaluating patients with a suspected cardiac source of embolus. TTE and TEE provide invaluable information regarding the majority of cardiac sources of embolus.

Streptokinase morbidity--more common than previously recognised.

Streptokinase is the thrombolytic agent most commonly used for the treatment of acute myocardial infarction. We report eight patients who developed late uncommon adverse reactions to streptokinase probably due to immune complex disease. The clinical manifestations included vasculitic rashes, abnormal renal and liver function tests and a syndrome resembling adult respiratory distress syndrome. Major adverse events with streptokinase such as stroke, bleeding and other allergic reactions, have been previously documented but the morbidity related to delayed reactions has not been widely recognised. These reactions produced significant morbidity resulting in prolonged hospital stay and may need to be considered in the decision to use streptokinase.