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Dive into the research topics where Robert D. Rifkin is active.

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Featured researches published by Robert D. Rifkin.


Journal of the American College of Cardiology | 1995

Comparison of proximal isovelocity surface area method with pressure half-time and planimetry in evaluation of mitral stenosis.

Robert D. Rifkin; Kathleen A. Harper; Dennis A. Tighe

OBJECTIVES This study sought to 1) compare the accuracy of the proximal isovelocity surface area (PISA) and Doppler pressure half-time methods and planimetry for echocardiographic estimation of mitral valve area; 2) evaluate the effect of atrial fibrillation on the accuracy of the PISA method; and 3) assess factors used to correct PISA area estimates for leaflet angulation. BACKGROUND Despite recognized limitations of traditional echocardiographic methods for estimating mitral valve area, there has been no systematic comparison with the PISA method in a single cohort. METHODS Area estimates were obtained in patients with mitral stenosis by the Gorlin hydraulic formula, PISA and pressure half-time method in 48 patients and by planimetry in 36. Two different factors were used to correct PISA estimates for leaflet angle (theta): 1) plane-angle factor (theta/180 [theta in degrees]); and 2) solid-angle factor [1-cos(theta/2)]. RESULTS After exclusion of patients with significant mitral regurgitation, the correlation between Gorlin and PISA areas (0.88) was significantly greater (p < 0.04) than that between Gorlin and pressure half-time (0.78) or Gorlin and planimetry (0.72). The correlation between Gorlin and PISA area estimates was lower in atrial fibrillation than sinus rhythm (0.69 vs. 0.93), but the standard error of the estimate was only slightly greater (0.24 vs. 0.19 cm2). The average ratio of the solid- to the plane-angle correction factors was approximately equal to previously reported values of the orifice contraction coefficient for tapering stenosis. CONCLUSIONS 1) The accuracy of PISA area estimates in mitral stenosis is at least comparable to those of planimetry and pressure half-time. 2) Reasonable accuracy of the PISA method is possible in irregular rhythms. 3) A simple leaflet angle correction factor, theta/180 (theta in degrees), yields the physical orifice area because it overestimates the vena contracta area by a factor approximately equal to the contraction coefficient for a tapering stenosis.


American Heart Journal | 1988

Value of fluoroscopy in the detection of coronary stenosis: influence of age, sex, and number of vessels calcified on diagnostic efficacy

Barry F. Uretsky; Robert D. Rifkin; Satish C. Sharma; P.Sudhakar Reddy

Although fluoroscopically detected coronary artery calcification is known to correlate with the presence of coronary artery stenosis, age, sex, and extent of calcification influence the strength of this association. To clarify its diagnostic potential, we performed fluoroscopy before coronary angiography in 600 patients and analyzed the results according to all three factors simultaneously. The sensitivity of fluoroscopy for significant stenosis exceeded 65% in all groups except women less than 45 years of age. Specificity exceeded 90% in patients less than 45 years and 85% in patients less than 55 years of age, and declined significantly with age. The number of vessels calcified was an important determinant of predictive value, except in those less than 45 years of age in whom even a single mild calcification markedly increased the chance of stenosis. In patients aged 45 to 64 years, calcification of two or three vessels substantially increased the chances of stenosis, but single-vessel calcification increased the risk only slightly. In patients more than 65 years of age, fluoroscopy was not helpful in detecting stenosis, regardless of the number of vessels calcified. Our findings were similar in men and women. We conclude that if both age and the number of vessels calcified are considered, fluoroscopy can provide useful information regarding the presence of stenosis in young and middle-aged patients.


Journal of the American College of Cardiology | 1984

Combined posteroanterior subepicardial fat simulating the echocardiographic diagnosis of pericardial effusion

Robert D. Rifkin; Jeffrey M. Isner; Barbara L. Carter; Mark S. Bankoff

The location and relative size of echo-free spaces observed by cardiac ultrasound have been considered reliable signs for distinguishing pericardial fat from fluid; spaces that are exclusively anterior have been considered to represent fat, while spaces that are exclusively or predominantly posterior have been considered to represent fluid. In the present study, the location and relative size of echo-free spaces in eight patients suggested the diagnosis of pericardial effusion; evaluation by computed tomography or thoracotomy, or both, in six and necropsy in two, however, disclosed that these echo-free spaces--posterior as well as anterior--were exclusively due to fat. Age appeared to be as important a predisposing factor as obesity in the accumulation of excess subepicardial fat. No M-mode or two-dimensional features were found to be reliable in differentiating fat from fluid, although excessive amplitude of the posterior pericardial echo on the M-mode study favored the diagnosis of fat. Thus, the finding of echo-free spaces by cardiac ultrasound, even when the posterior space is isolated or larger than an accompanying anterior space, is not necessarily indicative of pericardial fluid. In elderly patients, in particular, posterior echo-free spaces due to fat may invite an incorrect diagnosis of pericardial effusion or pericarditis. In patients in whom echo-free spaces represent an unexpected finding of cardiac ultrasound examination, computed tomography of the chest may be helpful in establishing whether they are due to fat or fluid.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 1997

Survival in Infarct Related Intramyocardial Dissection: Importance of Early Echocardiography and Prompt Surgery

Dennis A. Tighe; James J. Paul; A.R. Maniet; Joseph E. Flack; John D. Mannion; Robert D. Rifkin; Joel S. Raichlen

Infarct related intramyocardial dissection, an unusual mechanical complication associated with recent inferior/inferoposterior myocardial infarction, is characterized by a septal defect and a dissection tract that originates on the left side of the interventricular septum, extends beyond the septum into the right ventricular free wall, and subsequently re‐enters the right ventricle. The utility of echo‐cardiography for diagnosis has been described. Despite aggressive therapy, the prognosis of intramyocardial dissection is reported to be dismal. We describe the use of prompt echocardiography in two patients, which established the diagnosis of infarct related intramyocardial dissection allowing early definitive surgery and long‐term survival.


American Heart Journal | 1996

Pacemaker lead infection: Detection by multiplane transesophageal echocardiography

Dennis A. Tighe; Luis A. Tejada; James B. Kirchhoffer; Patricia Gilmette; Robert D. Rifkin; N.A. Mark Estes

Because a myocardial biopsy was not performed, we cannot rule out the possibility of myocarditis with intermittent exacerbations as an explanation for the patients symptoms and creatinine kinase elevations. However, the severity and sudden onset of the symptoms suggest that the process is acute myocardial infarction. In conclusion; we report a case of recurrent non-Q-wave myocardial infarction and cardiomyopathy associated with toluene abuse. Because of the increasing use of solvents as recreational drugs, toluene toxicity should be included in the differential diagnosis of myocardial infarction with normal coronary anatomic condition.


The Annals of Thoracic Surgery | 1998

Echocardiography Allows Safer Venous Cannulation During Excision of Large Right Atrial Masses

John A. Rousou; Dennis A. Tighe; Robert D. Rifkin; Richard M. Engelman; Joseph E. Flack; David W. Deaton; Charles A. Anene; Eugene A. Fernandes

BACKGROUND Excision of large right atrial masses requires bicaval cannulation and cardiopulmonary bypass. Safe venous cannulation can be accomplished only by knowing the exact intracavitary location and extension of the mass to avoid fragmentation. Transthoracic echocardiography and intraoperative transesophageal echocardiography, although helpful, cannot always define the exact intracavitary relationships of the tumor. METHODS We have used both intraoperative transesophageal and epicardial echocardiography to guide venous cannulation in 4 patients with large right atrial masses. Both echo images are used by the surgeon to select the exact site and method of cannulation to avoid fragmentation of the mass. Epicardial echocardiography complemented the images obtained by transesophageal echocardiography. RESULTS The technique of combined transesophageal and epicardial echocardiography allowed safe venous cannulation in all 4 patients. Each of the right atrial masses was safely excised using case-specific cannulation techniques guided by the echocardiographic images. CONCLUSIONS We propose the routine use of both intraoperative transesophageal and epicardial echocardiography in guiding venous cannulation for safe excision of large right atrial masses.


American Journal of Cardiology | 1993

Screening for Latent Coronary Artery Disease by Fluoroscopic Detection of Calcium in the Coronary Arteries

Robert D. Rifkin; Barry F. Uretsky

Abstract In a population comprised of patients with symptomatic coronary artery disease (CAD), it has been shown that the sensitivity and specificity of conventional fluoroscopy for detection of stenosis is good when age and extent of calcium are considered. 1 However, because coronary angiography is difficult to justify in the absence of active CAD, only the predictive value of a positive fluoroscopic test has been reported in asymptomatic subjects. 2,3 Moreover, the influence of gender, age, and number of arteries calcified has not been examined in this group. To clarify the potential of fluoroscopy for detecting latent CAD and to assess the effect of age, sex and severity of calcium on its diagnostic efficacy, we studied patients undergoing coronary arteriography for nonischemic heart disease who had no evidence of concomitant CAD.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 1996

Echocardiographic Findings in Rupture of Long False Tendons: Report of Two Cases.

Robert D. Rifkin; Kathleen A. Harper; Dennis A. Tighe; Nasser Elmansoury; Janet D'amours

Long left ventricular false tendons, which connect distant sites on the ventricular endocardium, are common incidental echocardiographic findings. We describe two cases in which rupture of such long false tendons produced unusual, highly mobile, intracavitary echo densities that could be mistaken for other important pathologies, such as thrombus or vegetation. The differentiation of ruptured long false tendons and intact short apical false tendons from other entities they may mimic is described.


Cardiovascular Surgery | 1995

Does interruption of normothermic cardioplegia have adverse effects on myocardium? A retrospective and prospective clinical evaluation

John A. Rousou; Richard M. Engelman; Joseph E. Flack; David W. Deaton; Robert D. Rifkin; Elmansoury A

A total of 154 patients who underwent isolated coronary revascularization (coronary artery bypass grafting) using retrograde, near-continuous, warm cardioplegia for myocardial protection, were arbitrarily divided into three groups according to the cumulative cardioplegic interruption (i.e. the sum total of all the short cardioplegic interruption periods, expressed as a percentage of the cardiac arrest period). Group 1 (39 patients) had < 20% interruption (mean(s.e.m.) 12.5(0.01)%), group 2 (82 patients) had 20-39% interruption (mean(s.e.m.) 30.1(0.01)%) and group 3 (33 patients) had > 40% interruption (mean(s.e.m.) 45.4(0.01%). The three groups were comparable except for longer clamp time in group 3 and a lower cardiac index in group 1. The mean number and duration of cardioplegic interruptions and reperfusions and multiple clinical outcomes were recorded. Clinical outcomes (Q) wave perioperative infraction, use of an intra-aortic balloon pump, mortality, and length of stay in the intensive care unit and hospital) were the same in all groups despite significant differences in percent, number and duration of interruption and reperfusion as well as cardiac arrest. The only significant differences found were in the level of creatine kinase-MB (CK-MB) and use of inotropes after surgery, both being higher in group 1 than in groups 2 and 3 (which is the opposite of what would be expected). Intraoperative hemodynamic (cardiac index and left ventricular ejection fraction) and metabolic evaluations (CK-MB, lactate production and oxygen extraction) in 22 additional patients who underwent coronary artery bypass grafting showed no significant differences between two groups having < 30% versus > 30% cumulative cardioplegic interruption. It is concluded that warm cardioplegic interruption as used clinically has no adverse effects on the myocardium in patients undergoing coronary revascularization. Warm retrograde near-continuous blood cardioplegia is an effective method of myocardial protection.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 1995

Two‐Dimensional Echocardiographic Identification of Peripheral Coronary Artery Ectasia in an Adult

Dennis A. Tighe; Kathleen A. Harper; Reed Shnider; Marianne Kalmbach; Robert D. Rifkin

Coronary artery aneurysms (ectasia) have been reported to be present in up to 4.9% of patients undergoing coronary angiography. In children with Kawasakis disease or coronary arteriovenous fistula, the transthoracic two‐dimensional echocardiographic findings associated with peripheral vessel aneurysms have been previously described. Echocardiographic imaging of peripheral coronary artery segments in the adult is difficult and to date only imaging of large, proximal coronary artery aneurysms has been reported. We report a case of an adult patient with angiographically documented extensive right coronary artery ectasia in which peripheral vessel aneurysms were identified with transthoracic echocardiography.

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Dennis A. Tighe

University of Massachusetts Medical School

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Barry F. Uretsky

University of Arkansas for Medical Sciences

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Elmansoury A

Baystate Medical Center

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