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Biomedical subjects

J Morganroth

Publications and source records attributed to J Morganroth.

At least 163 records · Page 9Linked to original sources

Tricuspid valve prolapse diagnosed by cross-sectional echocardiography.

Cross-sectional echocardiography utilizing the apical and longitudinal right ventricular inflow tract views was used to investigate the tricuspid valve in 64 patients with mitral valve prolapse and 16 controls who had no angiographic or echocardiographic evidence of mitral valve prolapse. The tricuspid valve leaflets and their coaptation point in systole were found to be below (towards the right ventricular apex) the level of the tricuspid valve ring in systole in all controls. Tricuspid valve prolapse, defined as the leaflet(s) of the tricuspid valve lying above the tricuspid valve ring level within the right atrium, was seen in 31/64(48 percent) of patients with mitral valve prolapse. The right ventricular inflow tract view demonstrated tricuspid valve prolapse most readily compared to the apical view, and 29 of the 31 patients with tricuspid valve prolapse had prolapse of at least two leaflets of the tricuspid valve. The 31 patients with both mitral and tricuspid valve prolapse, when compared to the 33 patients with mitral valve prolapse alone, had more symptomatology and abnormal physical findings.

Adult↗

Two dimensional echocardiography in mitral, aortic and tricuspid valve prolapse. The clinical problem, cardiac nuclear imaging considerations and a proposed standard for diagnosis.

The mitral valve prolapse syndrome may present with a variety of clinical manifestations and has proved to be a common cause of nonspecific cardiac symptoms in clinical practice. Primary and secondary forms must be distinguished. Myxomatous degeneration appears to be the common denominator of the primary form. The diagnostic standard of this form has not previously been defined because the detection of mitral leaflet tissue in the left atrium (prolapse) on physical examination or angiography is nonspecific. M mode echocardiography has greatly enhanced the recognition of this syndrome but has not proved to be the best diagnostic standard because of its limited view of mitral valve motion. The advent of two dimensional echocardiography has provided the potential means for specific identification of the mitral leaflet motion in systole and can be considered the diagnostic standard for this syndrome. Primary myxomatous degeneration with leaflet prolapse is not localized to the mitral valve. Two dimensional echocardiography has detected in preliminary studies tricuspid valve prolapse in up to 50 percent and aortic valve prolapse in about 20 percent of patients with idiopathic mitral valve prolapse.

Angiocardiography↗

Echocardiographic detection of coronary artery disease. Detection of effects of ischemia on regional myocardial wall motion and visualization of left main coronary artery disease.

M mode and cross-sectional echocardiographic studies at rest have been used to detect regional left ventricular wall motion abnormalities as a sign of hemodynamically significant coronary artery disease. These techniques have proved to be fairly specific but not highly sensitive. Detection of new regional wall motion abnormalities with cross-sectional echocardiography during exercise appeared practical in 80 percent of patients in preliminary studies; the finding of such abnormalities is highly specific for the presence of coronary artery disease and, with this approach, the sensitivity of echocardiography is improved. Thus, patients with anatomically severe coronary artery disease on angiography may not manifest an echocardiographic abnormality in regional wall motion even during exercise. The direct noninvasive detection of the left main coronary artery in up to 90 percent of patients studied with cross-sectional echocardiography using the short axis or apical approach, or both, has been well defined. A high sensitivity and specificity of detecting anatomically severe left main coronary artery disease using the criteria of both luminal impingement and the presence of high intensity echoes have been confirmed. Further advances in imaging techniques may allow for better definition of the coronary arterial tree.

Coronary Disease↗

Tricuspid regurgitation in tricuspid valve prolapse demonstrated with contrast cross-sectional echocardiography.

To determine the prevalence of tricuspid regurgitation in patients with tricuspid valve prolapse and to define further the criteria for the diagnosis of tricuspid regurgitation on contrast echocardiography, evaluation was made of 45 patients who had adequate contrast studies. There were four groups of patients: Group A, 10 healthy control subjects with no evidence of structural heart disease on cardiac catheterization; group B, 10 patients with classic clinical evidence of tricuspid regurgitation; group C, 10 patients with cross-sectional echocardiographic evidence of mitral valve prolapse without tricuspid valve prolapse; and group D, 15 patients with both mitral and tricuspid valve prolapse on cross-sectional echocardiography. Tricuspid regurgitation was sought in each group by using the subxiphoid echocardiographic approach with peripheral venous injection of saline solution. The diagnosis required the presence of microcavitations in both the inferior vena cava and hepatic veins for at least three consecutive cardiac cycles. Tricuspid regurgitation was observed in no patients in group A, 10 of 10 patients in group B, 0 of 10 in groups C and 6 of 15 (40 percent) in group D. Contrast cross-sectional echocardiography proved to be a reliable technique for identifying tricuspid regurgitation with a high degree of specificity and sensitivity. Patients with tricuspid valve prolapse had a 40 percent prevalence rate of tricuspid regurgitation. This finding may identify a subgroup that requires particularly careful clinical follow-up care.

Adolescent↗

Rheumatic mitral stenosis:cross-sectional echocardiographic analysis.

Twenty-one patients with rheumatic mitral stenosis diagnosed by both M-mode echocardiography and hemodynamic findings were subjected to detailed cross-sectional echocardiographic studies. The age of the patients ranged from 27 to 79 years with 76% females. Left ventricular longitudinal, short axis, and apical four-chamber cross-sectional echocardiographic views were obtained in each patient. Three predominant patterns of anterior mitral leaflet motion on left ventricular longitudinal view were observed and correlated with the severity of mitral stenosis: Pattern A (eight patients) with diastolic leaflet doming and restricted leaflet tip motion. Pattern B (eight patients) tip and body leaflet motion, and Pattern C (five patients) with the entire leaflet motion restricted. Mitral valve prolapse as a rebound phenomenon was observed in three patients who had marked leaflet doming in Pattern A and two had severe obstruction. The longitudinal cross-sectional echocardiography was superior to the apical view in assessing the diastolic doming motion of the anterior mitral leaflet. Thus, longitudinal cross-sectional echocardiographic analysis of the pliability and degree of doming of the anterior of the pliability and degree of doming of the anterior mitral leaflet is valuable in estimating the severity of mitral stenosis.

Adult↗

Echocardiographic features of atrioventricular and ventriculoatrial conduction.

The potential application of diagnostic ultrasound to understanding of the hemodynamic effects of various rhythm and conduction disturbances has not been fully explored. To investigate the change in cardiac function associated with various atrioventricular (A-V) sequencing intervals during cardiac pacing, simultaneous M mode and two dimensional echocardigraphic and hemodynamic studies were performed in 23 dogs. One to one A-V and ventriculoatrial (V-A) sequential pacing at cycle lengths of 400 and 300 ms revealed a stepwise reduction in left ventricular pressure and cardiac output as the A-V interval was changed from +100 to -100 ms. These reductions in cardiac hemodynamics were associated with decreases in left ventricular and increases in left atrial dimensions determined with echocardiography. Mitral valve excursion and the duration of valve opening remained constant over the entire range of A-V intervals. There was angiographic evidence of retrograde blood flow from the left atrium into the pulmonary venous system at an A-V interval of -50 and -100 ms, but no evidence of mitral regurgitation. Thus, correlative echocardiographic and hemodynamic studies can suggest multiple pathophysiologic mechanisms contributing to the decrements in cardiac function observed during tachyarrhythmias with intact A-V conduction as well as those occurring consequent to A-V nodal Wenckebach cycles.

Animals↗

A new approach to visualize the left main coronary artery using apical cross-sectional echocardiography.

Patients undergoing coronary arteriography were studied to evaluate the feasibility of use of cross-sectional echocardiography to detect the left main coronary artery. Visualization of the left main coronary artery from the cardiac apex was attempted using a cranial transducer angulation. With this approach, the left main coronary artery was adequately visualized in 27 of 35 consecutive patients (77 percent) who were prospectively evaluated; in 12 of the 27 the bifurcation was clearly seen. In 26 of the 27 patients cross-sectional echocardiography correctly assessed the patency of the left main coronary artery as judged with coronary angiography. One patient had a false positive echocardiographic study; there were no false negative studies. A comparison of the short axis versus apical cross-sectional techniques in another group of 30 patients revealed the superiority of the apical approach in visualization of the left main coronary artery and its bifurcation; combined use of both techniques allowed for a 93 percent (rate of) success. Thus, apical cross-sectional echocardiography permits visualization of the left main coronary artery and its bifurcation and, therefore, has the potential for detecting left main coronary obstructive lesions.

Adult↗

Early recognition of surgically correctable causes of excessive mediastinal bleeding after coronary artery bypass graft surgery.

In an attempt to establish criteria to enable recognition of patients with surgically correctable causes of excessive mediastinal bleeding, 250 patients undergoing coronary artery bypass graft surgery were reviewed. Ten (4 percent) required reexploration for excessive postoperative mediastinal bleeding and were compared with 95 consecutive control patients. There were no statistically significant differences in preoperative coagulation studies, use of aspirin or warfarin, number of vessels bypassed or bypass time. Mean mediastinal blood loss was statistically greater (p less than 0.001) in the reexploration group for the first 8 hours of the postoperative period than in the control group. Mean heterologous blood transfusion was 8.4 units in the reexploration group compared with 1.3 units in the control group. Based on analysis of the differences in mediastinal bleeding rates in the control and reexploration groups, we conclude that after coronary artery bypass graft surgery postoperative mediastinal bleeding of greater than 300 ml in the 1st hour, greater than 250 ml in the 2nd hours, and greater than 150 ml/hour thereafter suggests the presence of a surgically correctable lesion.

Blood Transfusion↗

Noninvasive diagnosis of the cardiomyopathies.

The presenting clinical features of the cardiomyopathies are nonspecific. Echocardiography is useful in detecting patients with cardiomyopathy and determining proper management. Echocardiography can be used to determine both cardiac structural measurements and cardiac function.

Aortic Stenosis, Subvalvular↗

Mechanism and prevention of cardiac arrhythmias in chronic hemodialysis patients.

We monitored, by the Holter method, 23 clinically stable maintenance hemodialysis patients for 5 +/- (SEM) 2 hours before hemodialysis, 5.0 +/- 0.5 hours during hemodialysis, and 13 +/- 3 hours after hemodialysis. Of 23 patients, 9 (39%) had unexpected frequent or complex ventricular arrhythmias recorded and after hemodialysis with a potassium dialysate bath concentration of 2.0 mEq/liter. Patients with ventricular arrhythmias were more likely to be using digoxin (8/9 vs. 1/4) and to have evidence of left ventricular hypertrophy (9/9 vs. 7/4 than were those patients without arrhythmias. Of these 9 patients with arrhythmias, 6 underwent repeat Holter monitoring during multiple dialysate protocols. Of the 6 patients, 4 had a significant reduction in the frequency of ventricular ectopy when a dialysate of 3.5 mEq/liter potassium was used (P < 0.05), but of these 6, 3 still had complex arrhythmias. The use, however, of a 3.5 mEq/liter potassium dialysate plus the administration of a 400-mg dose of quinidine sulfate orally 45 min prior to hemodialysis was successful in reducing ventricular ectopic frequency and complexity in all the patients studied. Conclusion. Maintenance hemodialysis patient using digoxin and with left ventricular hypertrophy have an unexpectdly high indicence of occult, potentoial serious, ventricular arrhythmias during and after hemodialysis, revealed by Holter monitoring. There is preliminary evidence that a low-potassium bath concentration may play a role in predisoposing patients to these arrhythmias. Further prospective studies with largaer number of patients will be needed, however, to evaluate the significance of these findings.

Adult↗

Spontaneous variability of complex ventricular arrhythmias detected by long-term electrocardiographic recording.

Variations in the frequency of complex ventricular arrhythmias were evaluated by consecutive 24-hour long-term electrocardiographic recordings over 4 days using a two-channel recorder and computer-assisted analysis system with a weighted relative mean error of 7.5 +/ 5% (SD). Twenty patients (mean age 58 +/- 9 years [SD] with various cardiac disorders were selected if they had a daily average of more than 30 ventricular ectopic complexes per hour. Twenty patients had ventricular couplets and 14 patients had ventricular tachycardia (at least triplets). The mean daily number of either couplets or ventricular tachycardia was subjected a four-factor nested analysis of variance to determine the sources of variation in ectopic frequency. Differences in hourly rates accounted for 30% of the variation in the frequency of ectopic complexes. Statistical methods were applied to determine the change in frequency of complex arrhythmias necessary to exceed that attributable to spontaneous variation alone at the p less than 0.05 level. Using a typical protocol, for example, comparing a 24-hour test period with a 24-hour control period would require a 65% decrease in mean hourly frequency of ventricular tachycardia and 75% reduction in the frequency of couplets to demonstrate therapeutic efficacy rather than a reduction due to spontaneous variation alone.

Adult↗

Detecting left main coronary artery disease by apical, cross-sectional echocardiography.

To test the feasibility of imaging the left main coronary artery (LMCA) noninvasively as a means of detecting left main coronary artery disease, we studied 73 patients who underwent cardiac catheterization and cross-sectional echocardiography. Fifty-two had a normal LMCA (controls) and 21 had significant obstruction (greater than or equal to 50% luminal reduction). The apical, tomographic, cross-sectional, phased-array, echocardiographic approach was used, and the LMCA was imaged in 52 of 73 patients (71%). In 34 of 36 controls (94%) the LMCA was correctly judged as having no luminal obstruction. In the other two, and asymmetric, high-intensity echo in one wall of the artery suggested atherosclerotic disease, but coronary angiography revealed no obstruction. In 12 of 16 patients (75%) in whom significant LMCA disease was imaged, obstruction was predicted by echocardiographic criteria of either luminal irregularity or an asymmetric, high-intensity echo in the arterial wall. This preliminary study suggests that cross-sectional echocardiography appears to be a feasible, noninvasive technique to image the LMCA and to detect hemodynamically significant luminal obstruction.

Adult↗

Cardiovascular complaints. Correlation with cardiac arrhythmias on 24-hour electrocardiographic monitoring.

Long-term ambulatory electrocardiographic (Holter) monitoring is frequently used to evaluate patients with various cardiovascular complaints, including palpitations, dyspnea, discomfort in the chest, dizziness, and syncope. In the present study, 518 consecutive 24-hour electrocardiographic recordings were reviewed to determine correlations between cardiac diagnoses, presenting complaints, and specific electrocardiographic abnormalities. Two hundred seventy-four patients (53 percent) had significant arrhythmias; 212 (41 percent) had significant ventricular arrhythmias, and 106 (20 percent) significant atrial arrhythmias, including 44 patients (8 percent) with both. No presenting complaint or cardiovascular diagnosis correlated closely with any specific cardiac arrhythmia. Major arrhythmias, including supraventricular and ventricular tachycardias, often occurred asymptomatically (in 44/54 and 37/40 patients, respectively); however, among 371 patients with accurate historic logs, only 176 (47 percent) had long-term electrocardiographic studies in which their typical symptoms occurred during the monitoring period. Fifty (13 percent) of the 371 patients had concurrence of their presenting complaints with an arrhythmia, and 126 patients (34 percent) had their typical symptoms associated with a normal electrocardiogram, which was helpful in excluding an abnormality of rhythm or conduction as the primary cause for their complaints.

Arrhythmias, Cardiac↗

Nonsustained ventricular tachycardia in ambulatory patients: characteristics and association with sudden cardiac death.

Thirty-seven patients with nonsustained ventricular tachycardia (greater than or equal to triplets) were identified retrospectively from a population of 518 consecutive patients referred for 24-hour Holter monitoring and studied to determine the prognostic significance of this finding. Ten of these 37 patients suffered sudden cardiac death during a mean follow-up of 19 +/- 5 months. Nine of 19 patients with a diagnosis of congestive cardiomyopathy or history of congestive heart failure died suddently compared to only one of the other 18 patients. No other patient data were predictive of sudden death. Remarkably, no characterisitc of the ventricular tachycardia including beats per episode, episodes per day, rate, prematurity index (RR1/QT) of the initiating beat, or the occurrence of associated arrhythmias was important prognostically. Thus, patients with congestive cardiomyopathy or congestive heart failure and nonsustained paroxysmal ventricular tachycardia are at a high risk for sudden death and are ideal candidates for prophylactic interventions.

Adolescent↗