Femoral vein delivery of contrast medium enhances transthoracic echocardiographic detection of patent foramen ovale.

OBJECTIVES: We postulated that femoral vein delivery of contrast medium because of streaming, might enhance precordial echocardiographic detection of patent foramen ovale. BACKGROUND: Although precordial contrast echocardiography is widely used to diagnose patent foramen ovale, this method is limited by poor sensitivity. Previous investigators have demonstrated enhanced detection of atrial defects by the dye-dilution technique after delivery of contrast medium into the inferior rather than the superior vena cava. METHODS: Transthoracic contrast examinations were performed in a randomly selected group of 70 patients (without previous history of cerebral or systemic embolus) undergoing cardiac catheterization. Paired contrast agent injections (10 ml dextrose in water/0.25 ml air) were administered from an upper extremity vein and femoral vein in each patient during spontaneous respiration, cough and Valsalva maneuvers. Studies were interpreted by an experienced echocardiographer unaware of the sequence and site of injections. Positive studies were semiquantitatively graded from +1 (minimal left ventricular opacification) to +4 (intense left ventricular opacification). Catheterization and echocardiographic assessment of patent foramen ovale were compared in 21 subjects. RESULTS: Patent foramen ovale was detected significantly more often during femoral vein versus upper extremity contrast delivery (23 of 70 patients [prevalence 33%] vs. 9 of 70 patients [prevalence 13%], p < 0.001). The intensity of left ventricular opacification was also greater during femoral vein contrast injection. Precordial echocardiography combined with femoral contrast delivery was significantly more sensitive than cardiac catheterization for assessment of patent foramen ovale (8 of 21 patients vs. 2 of 21 patients, p < 0.05). CONCLUSIONS: Femoral vein contrast delivery significantly enhances the ability of precordial contrast echocardiography to diagnose patent foramen ovale. Physiologic patency of the foramen ovale is more common (prevalence 33%) than previously documented.

Prinzmetal's angina with coronary artery spasm. Angiographic, pharmacologic, metabolic and radionuclide perfusion studies.

We studied the effects of coronary artery spasm on perfusion of the microvasculature in a patient with Prinzmetal's angina. Intracoronary injections of 99mTc and 131I-labelled macroaggregated human serum albumin were performed (1) at rest, (2) during spontaneous angina, (3) after the administration of nitroglycerin and (4) during pacing-induced spasm and the resultant scans compared. The resting scan was normal. Pain and spasm were associated with a perfusion defect that was localized to the anterior and inferior walls of the left ventricle. The localization of the perfusion defect corresponded with angiographically demonstrated spasm involving left anterior descending and distal circumflex coronary arteries. A subsequent myocardial infarction was localized by 43K scanning to the same perfusion area. Metabolic and parasympathetic stimulation studies were performed but were inconclusive. The patient's recurrent pains were ultimately controlled with large oral doses of isosorbide dinitrate.

Malignant hyperthermia susceptibility. A light and electron microscopic study of endomyocardial biopsy specimens from nine patients.

Cardiomyopathy develops in some individuals who have a susceptibility to malignant hyperthermia. We studied right ventricular endomyocardial biopsy specimens from nine patients defined as having this disorder because of positive caffeine contracture tests on skeletal muscle biopsy specimens. Three patients had clinical evidence of cardiomyopathy and six did not. Light microscopy showed cytoplasmic contraction bands, perinuclear clearing, and a mild to moderate variation in myocyte and nuclear size. Ultrastructurally cytoplasmic contraction bands were associated with cardiac villi, myofiberlysis, and myofibrillolysis. These changes and occasional breaks in the sarcolemma were regarded as artefacts of the biopsy procedure. Megamitochondriosis with accompanying degenerative changes in the mitochondria were also seen and probably indicate increased cell metabolism; vacuolation of the cytoplasm was regarded as an "aging" phenomenon. Thus, the biopsy specimens were abnormal, but the changes were artefactual or nonspecific and were not unique to this group of patients. Biopsy did not provide a morphological explanation for abnormal cardiac function.

Experience with ergonovine provocative testing for coronary arterial spasm.

We reviewed our experience with the ergonovine provocative test for coronary arterial spasm in 40 patients with pain in the chest believed to be angina pectoris and in one patient with a myocardial infarction and normal coronary arteries. Twenty-nine patients had normal coronary arteries, while 12 had mild to moderate lesions. Ergonovine maleate was administered incrementally in total cumulative doses of 0.25 mg to 1.2 mg. The effect of ergonovine on coronary arterial caliber was determined by comparing the arterial diameter from the angiogram obtained after administration of ergonovine with that from the control. Measurements were made at the same preselected points in both films and also at points of greatest response. Excluding the three cases with complete occlusion, the mean reduction in coronary arterial diameter at preselected points was 12 +/- 15 percent. When the points of greatest response were examined, the maximum reduction in coronary arterial diameter was less than 25 percent in 13 patients, 25 to 50 percent in 20 patients, and more than 50 percent in eight patients. The patterns of response included complete occlusion of a vessel in the three patients with variant angina, diffuse narrowing in 16, diffuse and focal narrowing in six, and spasm at the catheter tip in three patients. All patients with maximum reductions of more than 50 percent in coronary arterial diameter and six of those with maximum reductions of 25 to 50 percent had pain in the chest, but only the three with complete occlusion had associated changes in the S-T segment. Thus, the response in patients with variant angina represents one end of a spectrum of responses to administration of ergonovine. In addition, a large number of patients may have ergonovine-induced pain in the chest without electrocardiographic changes and only an intermediate degree of coronary arterial spasm.

Evolving indications for preoperative intraaortic balloon pump assistance.

Over a two-year period about 1,000 operations were performed with cardiopulmonary bypass. Intraaortic balloon pump assistance (IABP) was employed on 150 occasions, and a review of these has permitted clarification of the indications for its use. Sixty patients had IABP for carcinogenic shock either after infarction or cardiotomy, and 37 (62%) survived. Preoperative IABP in 90 high-risk patients resulted in survival for 79 (88%). The indications for prophylactic IABP included: (1) relief of severe pain, which occurred in 42 patients with acute coronary insufficiency, (2) improvement in the coronary perfusion pressure, which was accomplished in 20 patients with significant left main coronary artery occlusion or its equivalent, and (3) protection of left ventricular function, which war carried out in 28 patients with an LV ejection fraction of less than 0.40. The significance of the preoperative endocardial viability ratio (EVR) in relation to prophylactic IABP was also assessed: an EVR below 0.70 appears to be an indication for preoperative IABP.

Lisinopril in the treatment of hypertension: a Canadian postmarketing surveillance study.

A postmarketing surveillance study in 2273 Canadian office practices provided the largest body of clinical experience to date with the angiotensin-converting enzyme (ACE) inhibitor lisinopril in the treatment of mild to moderate essential hypertension. The principal emphasis in this uncontrolled study was safety, assessed in 10,289 patients. Patients with a diastolic blood pressure > 90 mmHg were considered for the study. Both previously untreated patients and those who were experiencing adverse effects from their current antihypertensive regimen were included. Lisinopril was begun at a dose of 10 mg/day. Subsequent dose adjustments, to a maximum of 40 mg/day, were made to achieve optimal blood pressure control (diastolic blood pressure < or = 90 mmHg or > or = 10 mmHg below baseline for > or = 4 weeks at the same dose). Therapy was continued for a minimum of 4 weeks to a maximum of 12 weeks, with patients examined every 2 weeks. The frequencies of adverse effects and laboratory abnormalities were analyzed in all treated patients. All 10,289 patients enrolled were considered in the analysis of safety. One or more adverse effects were reported for 1593 (15.5%) patients, and 802 (7.8%) withdrew from the study because of adverse effects. The most frequent adverse effects were cough (4.0%), dizziness (2.3%), headache (2.1%), asthenia (1.7%), and nausea (1.0%). The physicians' global assessment rated overall tolerability as very good or good for 77.1% of the patients. Antihypertensive effect was evaluated in 5886 patients who met the criteria for efficacy analysis. The criterion response was attained in 5141 (87.3%) patients, with 68.6% responding to 10 mg/day of lisinopril, 26.3% to 20 mg/day, and 3.2% to 40 mg/day (the other 1.9% responded at nonstandard doses). Lisinopril was safe and well-tolerated. Except for cough, class effects of ACE inhibitors were rarely encountered. The results of the efficacy analysis confirm the established efficacy of lisinopril in patients with mild to moderate essential hypertension.

Basement membranes of small cardiac vessels in patients with diabetes and myxoedema: preliminary observations.

Ultrastructural observations on the basement membranes of small vessels from hearts of patients with diabetes, myxoedema and neither disease collected post mortem, reveal that the membranes of those with diabetes are nearly three times as thick as those in normal hearts (P less than 0.001), while in patients with myxoedema they are twice normal thickness (P less than 0.001). A significant difference was demonstrated between the thickness of the basement membrane in patients with diabetes and those with myxoedema (P less than 0.001).

Case 1. Diabetes mellitus.

A sedentary 60-year-old man newly diagnosed with diabetes insists on seeing a cardiologist because he has read that diabetes damages blood vessels. Several questions submitted by participants and the corresponding answers (based on group discussion and on the actions taken for the real patient) are presented.

Anomalous origin of the right pulmonary artery: a 19-year follow-up.

Origin of a pulmonary artery from the aorta is a rare congenital defect which usually is fatal if not surgically corrected in infancy. Medical treatment often is unsatisfactory because of progressive heart failure. Described is a 19-year follow-up of a patient who underwent surgery at age three weeks to correct a right pulmonary artery from the aorta.

Exercise-induced left bundle branch block: a case report of false positive MIBI imaging and review of the literature.

Exercise-induced left bundle branch block is a relatively rare finding during exercise tolerance testing. A 36-year-old female with intermittent exercise-induced left bundle branch block, a MIBI study suggesting anterior ischemia and normal coronary arteries is reported. A review of the English and French language literature published from January 1985 to January 1996 is presented. Exercise-induced left bundle branch block has been reported in association with and without structural heart disease. Pooled mortality in the group with structural heart disease was 2.7% per year, and mortality was 0.17% per year when no structural heart disease was identified. Exercise-induced left bundle branch block has been reported to resolve with therapy. Noninvasive testing appears to have limited ability to detect or exclude coronary artery disease in this group. If a definitive cardiac diagnosis is required, strong consideration should be given to coronary angiography.

Right outflow tract obstruction by a pedunculated neurofibroma: case report and literature review.

Right outflow tract obstruction due to neurofibroma is rare, with only four cases identified in the world literature. Obstruction due to a pedunculated neurofibroma has never been reported. A 36-year-old woman with no known heart disease presenting with dyspnea, palpitations and chest pain was shown on echocardiogram to have a mobile right ventricular mass. Cardiac catheterization revealed normal coronary arteries and right ventricular outflow tract obstruction by a pedunculated mass, which was surgically removed and histologically proven to be a benign neurofibroma. Following surgery the patient's symptoms disappeared, with no recurrence three years postoperatively.

Leiomyosarcoma of the left atrium: case report and review of the literature.

Leiomyosarcomas are extremely rare primary cardiac tumours. A 46-year-old woman presenting with symptoms and signs of rapidly progressive left ventricular failure and apparent systemic lupus erythematosus was subsequently found to have a grade III/III left atrial leiomyosarcoma which was confirmed surgically. Pathology showed a cellular neoplasm arranged in fascicles with multinucleated giant cells, with areas of high grade sarcomatous change. The patient died seven months postoperatively with intractable heart failure. At autopsy, tumour infiltrated the pericardium, both atria and the right ventricle, with invasion of the diaphragm and posterior mediastinum. The current world literature is reviewed with respect to this rare and often misdiagnosed tumour.

Angiotensin-converting enzyme inhibition in myocardial infarction--Part 1: Clinical data.

There is an increasing body of clinical trial evidence to support the use of angiotensin-converting enzyme (ACE) inhibitors in the management of patients following myocardial infarction (MI). Enthusiasm for the use of ACE inhibitors in the acute phase of MI had previously been tempered by the adverse results of an early trial. However, exciting new information is available from several large, randomized studies that has not only quelled those initial concerns but also attests to the efficacy of using this class of medication in the first 24 h after an acute MI. A Canadian National Opinion Leader Symposium was held in November 1995 to review the results of the major ACE inhibitor clinical trials and to discuss key issues and controversies surrounding their use in acute MI. The focus of this paper, the first of two parts, is on the results of the major ACE inhibitor clinical trials.

Angiotensin-converting enzyme inhibition in myocardial infarction--Part 2: Clinical issues and controversies.

Over the past 10 years, several clinical studies have concluded that, in patients already receiving conventional therapies, angiotensin-converting enzyme (ACE) inhibitors further reduce the risk of death following myocardial infarction (MI). Post-MI ACE inhibitors have proven to be effective as long term therapy in high risk patients as well as when used for much shorter periods in a broad patient population. However, while considerable mortality data have been collected, the effects of ACE inhibitors post-MI on other cardiovascular outcomes have not been as well documented. In addition, a number of issues regarding the most effective use of these agents remain unresolved. This paper, the second of two parts, focuses on the clinical issues and controversies surrounding the use of ACE inhibitors following acute MI. The effects of ACE inhibitors on the outcomes of sudden death, nonsudden death, recurrent angina, mitral regurgitation and left ventricular dysfunction are reviewed and potential mechanisms of action are proposed. In addition, ACE inhibitor therapy is discussed in terms of patient selection criteria, choice of agent, optimal dosing regimen, concomitant use of other therapies and relative costs of treatment. Finally, potential mechanisms of action of ACE inhibitors are proposed for each of the outcomes examined.

Comparison of technetium-99m pyrophosphate and technetium-99m methylene diphosphonate with variable amounts of stannous chloride in the detection of acute myocardial infarction.

The authors prospectively compared the ability of Tc-99m pyrophosphate (PYP) and Tc-99m methylene diphosphonate (MDP) to detect acute myocardial infarctions. The agents used were PYP (12 mg) with 3.4 mg of stannous chloride, MDP (10 mg) with 1.0 mg of stannous chloride, and MDP (10 mg) with 3.4 mg of stannous chloride. Imaging was performed on three consecutive days on 34 patients with proven myocardial infarctions, using the same agent on the first and third days of the study and an alternate agent on the second day. Agents were assigned randomly to each of six groups of patients. First images were obtained an average of 3.7 days (range, one to six days) following myocardial infarction. Seventeen of 23 patients (75%) had images positive for acute myocardial infarction with Tc-99m PYP, whereas only two of 21 patients (9.5%) had positive studies with Tc-99m MDP with 3.4 mg of stannous chloride and one of 24 patients (4.2%) had positive studies with Tc-99m MDP and 1.0 mg of stannous chloride. All three myocardial infarctions detected by Tc-99m MDP were extensive and transmural. When MDP and PYP were both positive in the same patient, the apparent size of the myocardial infarction was much smaller with the MDP. It is concluded that MDP can detect only large myocardial infarctions, has poor localization in the infarcted tissue, and varying the stannous chloride content of the preparation does not improve the ability of MDP to detect acute myocardial infarctions.

Leaking Glenn anastomosis demonstrated by first pass radionuclide angiography.

First pass radionuclide angiography was used to demonstrate a leaking Glenn anastomosis at the superior vena cava--right atrial junction as well as tricuspid atresia and a ligated persistent left superior vena cava. First pass radionuclide angiography may demonstrate anatomic configurations not obvious at cardiac catheterization and can be useful for adults with complicated congenital heart disease, particularly when biplane or multiple view angiography is not possible. Lung perfusion imaging can lead to an incorrect diagnosis of pulmonary embolism if the presence of a Glenn anastomosis in not known.