Papillary muscle rupture after chordal sparing mitral valve replacement.

Complete papillary muscle rupture is a catastrophic complication of acute myocardial infarction which usually leads to acute severe mitral regurgitation requiring urgent or emergent surgery. A case in which this complication occurred after chordal sparing mitral valve replacement is described. The severed papillary muscle was removed surgically. The incidence and natural history of papillary muscle rupture occurring after chordal sparing mitral valve replacement for ischemic mitral insufficiency is not known.

Incidence of unwarranted implantation of permanent cardiac pacemakers in a large medical population.

Because of allegations that the implantation of many permanent cardiac pacemakers has been unjustified, we reviewed the indications for all new pacemakers implanted at 30 hospitals in Philadelphia County between January 1 and June 30, 1983, and paid for by Medicare. Complete chart data were evaluated for 382 implants. We determined whether the indications for implantation were appropriate and adequately documented on the basis of standard clinical practice. Implants were classified as possibly indicated primarily because of inadequate diagnostic evaluation (63 percent) or inadequate documentation of an accepted indication (36 percent). Implants were classified as not indicated primarily because a rhythm abnormality was incorrectly identified as a justifiable indication (84 percent). We found that 168 implants (44 percent) were definitely indicated, 137 (36 percent) possibly indicated, and 77 (20 percent) not indicated. Unwarranted implantation was both prevalent (73 percent of hospitals had an incidence of 10 percent or more) and independent of the type of hospital (university teaching, university-affiliated, and community hospitals). The additional tests most often required to clarify the need for a pacemaker in inadequately evaluated cases included electrophysiologic studies (37 percent) and ambulatory monitoring (31 percent). We conclude that in a large medical population in 1983, the indications for a considerable number of permanent pacemakers were inadequate or incompletely documented.

Technetium-99m pyrophosphate scintigraphy for the detection of acute myocardial infarction. How useful is it?

To evaluate the contribution of Tc-99m pyrophosphate scintigraphy (TPS) on the overall management of patients suspected of having acute myocardial infarction (AMI), hospital records of 58 consecutive patients who underwent TPS, were evaluated in depth. The results indicate that TPS was essential for the diagnosis of AMI in 16% of the patients. TPS was most rewarding in perioperative patients and in patients with borderline or uninterpretable electrocardiographic and enzyme changes. Also, in some cases, TPS was able to confirm or exclude the diagnosis of AMI prior to the confirmation by serial electrocardiograms (ECG) and serial enzyme changes. TPS was less rewarding in patients with clinically low index of suspicion for AMI. It may also be confusing in patients with high clinical likelihood of AMI and a history of prior myocardial infarction because of the possibility of persistently positive TPS in some of these patients. Considering the limitations of ECGs, the cardiac enzymes, and atypical clinical presentations in the patient population we evaluated, TPS appears to be fairly accurate when the scintigraphic findings are compared with the final diagnosis at the time of discharge from the hospital.

Spontaneous recovery from cardiogenic shock and renal failure.

A patient is described with an unexpected and spontaneous recovery from cardiogenic shock and acute severe oliguric renal failure despite her refusal to receive appropriate therapeutic action. The uniqueness of this patient's course and the need to individualize ethical decisions are emphasized.

Pericardiocentesis using echocardiography.

Echocardiography is the procedure of choice for the detection and localization of pericardial effusion. It should be performed in all patients prior to elective pericardiocentesis to confirm the diagnosis and to determine the size and location of the effusion in order to minimize the risk and to maximize the yield of pericardiocentesis. When pericardial tamponade is suspected, echocardiography should be performed, time permitting, to document the presence of effusion, because other clinical entities, such as right ventricular failure, may mimic tamponade. Additionally, the finding of diastolic posterior motion of the right ventricular wall, or "diastolic collapse" of the right ventricle, is further evidence for the presence of tamponade and, at times, may eliminate the need for invasive hemodynamic diagnosis. Echocardiography is also useful when performed during pericardiocentesis, to evaluate the size and location of the effusion as the procedure progresses. Contrast echocardiography can determine the position of the pericardiocentesis needle quickly and safely. Thus the appropriate use of echocardiography has increased the safety and improved the yield of diagnostic and therapeutic pericardiocentesis.

Abnormal thallium-201 scans in patients with chest pain and angiographically normal coronary arteries.

We reviewed the exercise thallium-201 (TI-201) scans and clinical data of 41 patients with chest pain and normal coronary arteries to identify clinical factors associated with "false-positive" studies. Exercise TI-201 studies were performed before angiography and often precipitated referral. Sex, beta-blocker therapy, anginal pattern, and results of exercise electrocardiography were evaluated and compared with TI-201 imaging. A negative TI-201 study was the most common finding (p less than 0.005). Of the 41 patients, 11 (27%) had abnormal exercise TI-201 scans. No clinical factor was significantly associated with a false-positive TI-201 scans. Of the 11 patients with abnormal scans, 9 had greater than or equal to 1 cardiac abnormality: right bundle branch block in 2, mitral valve prolapse in 3, paroxysmal atrial fibrillation in 2, abnormal left ventricular diastolic pressure in 3, and left bundle branch block in 1. Thus, (1) when results of exercise TI-201 imaging are used to refer patients for angiography, "false-positive" TI-201 studies are common; (2) sex, beta blockade, anginal pattern, and results of exercise electrocardiogram are not useful predictors of a false-positive TI-201 study; and (3) patients with chest pain, normal coronary arteries, and abnormal TI-201 scans frequently have other cardiac abnormalities.

Primary pulmonary hypertension: M-mode and two-dimensional echocardiographic findings.

In two young men subsequently found to have primary pulmonary hypertension, echocardiographic findings suggested an atrial septal defect. Additionally, contrast echocardiography demonstrated right-to-left shunting at the atrial level. Cardiac catheterization demonstrated severe pulmonary hypertension with patent foramen ovale. Thus, primary pulmonary hypertension may result in findings similar to atrial septal defect on echocardiography, particularly if a foramen ovale is present.

Quantitative thallium-201 exercise scintigraphy for detection of coronary artery disease.

In 140 patients with chest pain quantitation of regional myocardial TI-201 activity was performed by serial scintigraphic images after treadmill exercise. Criteria for an abnormal thallium scintigram included: (a) greater than or equal to 25% persisted reduction in TI-201 uptake in anterolateral, anteroseptal, posterolateral, and inferoapical segments, or greater than or equal to 35% reduction in the inferior segment; (b) an initial defect with delayed redistribution; and (c) abnormal TI-201 washout. Of 110 patients with significant coronary artery disease (CAD), 100 had abnormal TI-201 scintigrams, while 27 of 30 patients with angiographically normal coronary arteries had normal scintigrams; 91% sensitivity, 90% specificity, and 97% predictive accuracy. Sensitivity and specificity were not significantly different when the 95 patients with diagnostic (greater than or equal to 85% maximum heart rate) and 45 with inconclusive (less than or equal to 85% maximum HR) Ex tests were compared. Comparison of qualitative and quantitative image analyses in a subset of these patients showed that both specificity and multivessel disease prediction were greater when the quantitative approach was used (90 against 73% and 78 against 39%, respectively). Sensitivity for CAD detection was reduced by 10% with visual interpretation alone. Thus, quantitative exercise TI-201 scintigraphy appears highly sensitive and specific for CAD detection in patients with chest pain.

Prognostic significance of resting anterior thallium-201 defects in patients with inferior myocardial infarction.

To determine whether Tl-201 scintigraphy performed at rest during the late hospital phase of inferior myocardial infarction can predict subsequent coronary events, 25 patients with historical, enzymatic, and electrocardiographic criteria of transmural inferior infarction underwent serial imaging with computer quantification 7-35 days after admission. All 25 patients had inferior defects, and 13 (52%) also had anterior defects implying stenosis of the left anterior descending coronary artery. The patients were divided into those with inferior and anterior perfusion defects (Group 1) and those with inferior defects alone (Group 2). In Group 1, three patients had persistent defects in the anterior wall and ten had initial defects with redistribution. New or recurrent coronary events--which included new onset or progression of angina pectoris, sudden death, reinfarction, and congestive heart failure--were recorded over an average 7.2 months of followup (range 3-9 mo) for all patients. Ten of 13 (77%) patients in Group 1 had 17 coronary events and four of 12 (33%) patients in Group 2 had six coronary events (p < 0.02). Nine patients in Group 1 and three in Group 2 developed angina (p < 0.03). The apparently increased prevalence in Group 1 of sudden death (8% against 0%), reinfarction (8% against 0%), and congestive heart failure (46% against 25%) was not statistically significant. Thus resting Tl-201 scintigraphy with computer quantification is a highly sensitive method to detect inferior myocardial infarction even in the late hospital phase. Moreover, it appears to identify those patients with inferior infarction at high risk for subsequent coronary events, presumably due to stenosis of the left anterior descending coronary artery.

Thallium-201 scintigraphy at rest in ischemia and infarction.

Serial imaging of the myocardium in the resting state after intravenous administration of thallium-201 can be employed to differentiate between ischemia or under-perfusion and myocardial infarction or scar. Redistribution of thallium with filling-in of defects on delayed images or rest can be observed in myocardial regions supplied by stenotic coronary arteries (greater than or equal to 70% narrowing). These myocardial segments usually exhibit normal or hypokinetic wall motion. Persistent defects over a two to three hour imaging period at rest correlate highly with Q waves on the electrocardiogram and akinetic or dyskinetic wall motion on ventriculography. Thallium scintigraphy can be successfully utilized for detecting and localizing acutely infarcted myocardium. Sensitivity for infarct detection is higher in the first 24 hours after the onset of chest pain, although with computer-assisted quantitative analysis of images sensitivity for late detection (ten to fourteen days post myocardial infarction) may be improved. Multivessel disease can be predicted in many patients with acute inferior myocardial infarction by demonstrating anteroseptal wall defects with delayed redistribution on rest images prior to hospital discharge. Patients who demonstrate inferior wall persistent defects (infarction) with anterior wall redistribution (hypoperfusion/ischemia) have a worse prognosis characterized by an increased frequency of recurrent angina and infarction compared to the group with only inferior defects. Thallium scintigraphy may also be useful in assessing myocardial infarct size. Patients with large defects during the acute phase of infarction have significantly higher early and late mortality.