[Diagnostic accuracy of tomographic myocardial imaging for evaluation of aortocoronary graft patency]

INTRODUCTION AND OBJECTIVES

Conventional ergometry has limitations in the evaluation of coronary artery bypass graft patency. The aim of the present study was to determine the efficacy of exercise single photon emission tomography with 99mTc-compounds for the diagnosis of coronary artery bypass grafts disease.

PATIENTS AND METHODS

The state of sixty-seven coronary artery bypass grafts (31 with mammary artery, 36 with safein vein; 35 to left descending anterior artery, 15 to circumflex and 17 to right coronary artery) were analyzed retrospectively in 38 patients (mean age 63+/-8.7; 35 men). The time that elapsed between the coronary surgery and the exercise tomography was 9,7 years. In 16 cases, exercise tomography was performed with 99mTc-MIBI and in the 22 remaining with 99mTc-tetrofosmin. In 6 cases, dipiridamol was administred simultaneously during an insufficient exercise test.

RESULTS

Sensitivity (73.1%), specificity (93%), positive predictive value (86.3%), negative predictive value (84.4%), global value (85%), positive likelihood ratio (10.4) and negative likelihood ratio (0.29) of exercise tomography were significantly (p<0.01) better than those obtained with the exercise test alone (53.8%, 43.6%, 38.9%, 58. 6%, 47.7%, 0.95 and 1.06, respectively).

CONCLUSIONS

Exercise tomography with 99mTc-compounds is a highly effective for the detection of coronary artery bypass grafts disease.

[Cardiac tamponade and Kaposi's sarcoma]

The case of a 31 year-old intravenous drug addict female patient with infection by the human immunodeficiency virus who had recurrent cardiac tamponade and who was diagnosed by pericardic biopsy as Kaposi's sarcoma is reported. The patient demonstrated involvement by cutaneous, mucosal, lymph node and probably pleuropulmonary Kaposi's sarcoma. Thoracic radiography, computerized tomography and echocardiography only showed the presence of pericardic effusion. Neither did the pericardic fluid obtained by pericardiocentesis provide any significant ethiologic data. Only the pericardic biopsy showed the typical lesions of Kaposi's sarcoma in this localization confirming diagnosis. This is the first case of pericardic Kaposi's sarcoma described in an alive patient and the difficulties of achieving the diagnosis of the cardiac involvement by Kaposi's sarcoma in AIDS patients are commented upon.

Cardiac tamponade as the initial manifestation of acute leukemia: report of a case and review of the literature

An 18-year-old woman with acute monoblastic leukemia presenting with cardiac tamponade is reported. Subxiphoid pericardiotomy was performed, and blast cells were observed in the pericardial fluid. The leukemia was refractory to chemotherapy and the patient died at three months from diagnosis, without recurrence of the pericardial effusion. In the review of the literature, only ten cases of cardiac tamponade as the first manifestation of acute leukemia have been found.

Electroversion after verapamil administration

Forty-nine consecutive patients (44 with atrial fibrillation and five with atrial flutter) received 10 mg of verapamil five to seven minutes before elective electroversion, to evaluate the feasibility of the latter while verapamil effects were present. Excluded were patients with moderate-to-severe heart failure, acute myocardial infarction, mean ventricular rate lower than 70 beats/minute, those receiving any antiarrhythmic drug other than digoxin, and those in whom sinus node dysfunction was suspected. In six patients, eight complications took place: four instances of hypotension (systolic blood pressure below 80 mm Hg), two instances of junctional escape rhythm (47 and 63 beats/minute) and two instances of junctional tachycardia. In all four instances of hypotension, return to normal values of blood pressure was spontaneous (within five minutes in three patients). Rhythm disturbances were transient, without clinical relevance. This study suggests that electroversion can be safely carried out during clinical action of verapamil in properly selected patients, and that occasional, self-limited hypotension is the only complication of clinical significance to be expected.