Accelerated junctional escape rhythm with retrograde P waves through alternating slow and fast pathways.
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Biomedical subjects
Publications and source records attributed to P Samet.
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Skeletal muscle ventricles (SMV) were constructed from canine left latissimus dorsi muscle. The animals were divided into three groups: group A (n = 5), SMVs rested 4 weeks without electrical conditioning; group B (n = 6), SMVs rested 4 weeks and then electrically conditioned for 6 weeks; group C (n = 5), SMVs rested 18 weeks without electrical conditioning. At the end of each protocol, the SMVs were acutely tested by connecting them to a mock-circulation device. The SMVs in group C developed stroke work at physiologic preloads superior to any previously reported, as high as 194% of left ventricular stroke work at afterloads of 80 mmHg. The SMVs in group B developed work outputs equivalent to 53% of the left ventricle, which is still more than four times that of the right ventricle. The results show that it is possible to harvest sufficient work from skeletal muscle ventricles to fully replace cardiac function at physiologic preloads.
Forty-four elderly patients (mean age 80 +/- 7 years) with elevated left ventricular outflow tract velocities and corresponding outflow tract gradients documented by continuous wave Doppler are reported (mean peak gradient 50 +/- 28). They had severe left ventricular hypertrophy, small left ventricular end-diastolic dimensions, and supernormal ejection fractions. Thirty-nine percent had a history of hypertension. They were predominantly female, had uniform concentric left ventricular hypertrophy, and had a high incidence of congestive heart failure. Diastolic function was found to be reduced in the elderly group compared to young patients with hypertrophic cardiomyopathy and to age- and sex-matched normal controls. It is concluded that most elderly patients with increased left ventricular outflow tract velocities are etiologically distinct from young patients with hypertrophic cardiomyopathy.
We describe a syndrome of fever, pericarditis, and symptomatic pericardial effusion beginning 2 months after transvenous insertion of a permanent pacemaker in a 75-year-old woman. The syndrome improved dramatically following pericardiocentesis and resolved after subsequent administration of indomethacin. Although right ventricular perforation during pacemaker insertion was not recognized, inadvertent perforation leading to the postcardiotomy syndrome is postulated.
Left ventriculography has become the single most important procedure in the evaluation of cardiac function. This study reevaluated the refinements of catheter and power injector technology to assess recommendations of past years and establish new principles for optimum ventriculography. Ventriculograms from 102 patients undergoing left heart catheterization and coronary arteriography for coronary, valvular, and myocardial heart disease served as the test sample. Three styles of #7F high-flow 110-cm pigtail catheters were utilized. One had 12 sideholes while the other two had six sideholes positioned nearer the base of the curl. Analysis of ventriculographic quality of each angiogram was performed by three of the authors independently and subsequently together. Five variables were analyzed for their effect on the diagnostic quality of the angiogram: 6-hole catheters, 12-hole catheters, volume of contrast, flow rate, and location of injection. Once these analyses were complete, the effect of combinations of these variables was tested to determine their effect on angiographic quality. The first combination included contrast volume and flow rate. The second combination compared contrast volume and flow rate when utilized with 6- or 12-hole catheters. The third combination tested the 6- and 12-hole catheters in the apex or inflow locations. A multivariate contingency analysis was used to define relationships between the variables and the quality of the angiogram obtained. As independent variables, catheter style, volume of contrast, flow rate, and location of injection did not influence angiographic quality. However, the apex as a location of injection was the single most consistently important determinant of ventricular angiographic quality.(ABSTRACT TRUNCATED AT 250 WORDS)
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Alcoholic cardiomyopathy usually has a poor prognosis, but the case presented here documents a dramatic regression of left ventricular dysfunction in a patient with alcoholic cardiomyopathy. Ejection fraction determined by echocardiography increased from 12% at the time of presentation to 45% 10 weeks later. This was associated with clinical resolution of congestive heart failure and a decrease in cardiac and left ventricular size documented by chest x-ray and echocardiography.
Twenty-five consecutive elderly patients with suspected aortic stenosis underwent continuous-wave Doppler echocardiography followed by cardiac catheterization. Doppler-derived calculations of peak and mean aortic valve gradients were compared with catheterization-derived values of peak-to-peak, peak and mean gradients. The best correlation was found between Doppler- and catheterization-derived mean gradients (r = 0.89). A Doppler-derived measure of the timing of peak aortic flow velocity (modified time-to-peak velocity/modified left ventricular ejection time) successfully separated those with gradients above or below 50 mm Hg and also helped to avoid over- or underestimation of aortic valve gradients by Doppler.
Congestive heart failure, unstable angina, and moderate mitral regurgitation improved after double-vessel angioplasty in a 41-year-old woman who was considered inoperable because of high risk of bypass surgery. With the concomitant use of balloon counterpulsation, angioplasty reduced the cross-sectional stenosis in the left anterior descending coronary artery from 98 to 20% and in the left circumflex coronary artery from 90 to 0%. The right coronary artery was completely occluded and angioplasty was not attempted. The ejection fraction was 17% prior to angioplasty and 50% 2 months later at follow-up.
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This prospective study was performed to determine whether complications that occur immediately before or after the time of scheduled catheterization are as much disease-related as procedure-related. During 24 months all complications associated with 1,606 diagnostic cardiac catheterizations were recorded if they occurred from 24 hours before the time the procedure was scheduled to 72 hours later, longer if complications were clearly procedure-related. Pseudo complications are spontaneous medical or surgical incidents that occur during the 24-hour period before catheterization is scheduled to be performed. Procedure-related complications are incidents that occur during or after the catheterization procedure. There were 13 (0.81%) procedure-related complications but not deaths. There were 13 (0.81%) pseudo complications including 4 (0.24%) deaths. All complications were similar in nature except for 3 instances of vascular injury, which were procedure-related. Pseudo complications occur as commonly as procedure-related complications and at times are more severe. Complications occurring before catheterization are related to the underlying disease process and not medical intervention. It is likely that similar disease-caused incidents occur after a catheterization and are not necessarily procedure-related.
A 68-year-old white male underwent permanent pacemaker implantation with an atrial synchronous ventricular inhibited pulse generator (Medtronic model 2409) because of syncope and abnormal H-V interval of 70 ms. Paroxysmal bouts of pacemaker associated tachycardia were subsequently recorded on several occasions, initiated and terminated by spontaneous ventricular premature beats. The mechanism for the occurrence of the tachyarrhythmia is discussed in detail and the functional characteristics of the pulse generator are described. Replacement of the unit with a different pacer device prevented further occurrence of the arrhythmia.
M-mode and two-dimensional echocardiographic evaluation of a patient with rheumatic heart disease and an atrioventricular sequential pacemaker with a coronary sinus lead showed an echo-producing mass in the left atrium. A repeat study after the coronary sinus lead was replaced by a right atrial screw-in lead revealed the disappearance of the echo-producing mass.
Echocardiographic recordings from a patient with a prosthetic mitral valve revealed echoes within the left ventricular cavity that mimicked the motion pattern of a "normal" anterior mitral leaflet. The echo pattern was continuous, recorded from multiple views, and by two-dimensional images it was localized to the level of the papillary muscles. Although thrombus and vegetation are possibilities, this echo probably originates from a pliable chordal structure severed but not removed at the time of surgery. The apparent responsiveness to hemodynamic influences was striking, and we suggest that the prevalence and pathophysiologic implications of such findings are of potential import.
A 36-year-old man was found to have severe pulmonary hypertension and a right-to-left shunt secondary to a patent ductus arteriosus. Attempt at surgical closure was unsuccessful. The patient was followed up for 21 years, and his only significant medical problem is leg weakness to moderate exertion.