BACKGROUND: The diagnostic accuracy of cardiac single photon emission computed tomography (SPECT) is limited by image-degrading factors, such as heart or subject motion, depth-dependent blurring caused by the collimator, and photon scatter and attenuation. We developed correction approaches for motion, depth-dependent blur, and attenuation and performed a multicenter validation. METHODS AND RESULTS: Motion was corrected both transversely and axially with a cross-correlation technique. Depth-dependent blurring was corrected by first back-projecting each projection and then applying a depth-dependent Wiener filter row by row. Attenuation was corrected with an iterative, nonuniform Chang algorithm, based on a transmission scan-generated attenuation map. We validated these approaches in 112 subjects, including 36 women (20 healthy volunteers, 8 angiographically normal patients, and 8 patients with coronary artery disease [CAD] found by means of angiography) and 76 men (23 healthy volunteers, 10 angiographically normal patients, and 43 patients with CAD found by means of angiography). Either technetium 99m or thallium 201 was used for emission; either gadolinium 153 or Tc-99m was used for transmission. Images were reconstructed and blindly interpreted with a 5-point scale for receiver operating characteristic analysis in 2 ways: motion correction plus a Butterworth filter, and combined motion and blur and attenuation corrections. The interpretation by means of consensus was for the overall presence of CAD and vascular territory. The receiver operating characteristic curves for overall presence and each of the 3 main coronary arteries were all shifted upward and to the left and had larger areas under the curve, for combined corrections compared with motion correction and Butterworth. Sensitivity/specificity for motion correction and Butterworth were 84/69, 64/71, 32/94, and 71/81 overall for the left anterior descending, the right coronary artery, and circumflex territories, respectively, compared with 88/92, 77/93, 50/97, and 74/95, respectively, for the combined corrections. CONCLUSIONS: The proposed combined corrections for motion, depth-dependent blur, and attenuation significantly improve diagnostic accuracy, when compared with motion correction alone.

Coronary Disease↗

PubMedDate not supplied

Acute hemodynamic effects of bufuralol: a beta-adrenoceptor blocking drug with vasodilatory effects.

Simultaneous hemodynamic and equilibrium radionuclide function measurements were performed at rest and during exercise before and 75 min after oral administration of 30 mg bufuralol, a nonselective beta-adrenoceptor blocking drug, in 10 patients with stable angina pectoris. Acute beta-blockade with bufuralol resulted in a reduction of exercise-stimulated heart rate, Systolic blood pressure, and cardiac index. There was, however, also a fall in diastolic blood pressure and end-diastolic volume index, and an improved global left ventricular ejection fraction, without a change in total vascular resistance, suggesting an acute vasodilator effect. regional analysis revealed that this beneficial effect was particularly present in ischemic segments of the left ventricular wall where regional function increased. Thus, bufuralol is a beta-adrenoceptor blocking agent with additional peripheral vasodilating properties.

Adrenergic beta-Antagonists↗

PubMedDate not supplied

[Longitudinal aging research over 20 years. Electrocardiogram, blood pressure, body weight, pulse wave velocity, accommodation latitude and retinal arteries of the eye].

We report on a longitudinal study of 80 men - from 10-60 years old at the beginning of the study - in the period 1955-1975, giving the results of ECG, blood pressure, body weight, vital capacity and other measures. A striking change was noted in the ECG, with the axis deviation shifting with age to the left. It is highly significant that the QRS-complex remained stationary, giving an individual indication for the entire life-time. Heart frequency, QRS duration and wave amplitude showed a slight decrease with age, whereas PQ and QTc distances reveal a slight prolongation in the 20 years. The most serious pathologic changes are myocardial infarcts, 2 among 80 working men. Blood pressure becomes higher with age but essential hypertension was seen only in 11.25%. A real health risk is the combination of permanent hypertension and obesity (3 deaths). Vital capacity reaches its maximum between 20 and 30 years of age and then diminishes slowly. The pulse wave velocity augments with aging. Other results are reported in detail.

Accommodation, Ocular↗

PubMedDate not supplied

Complications in patients with cloth-covered Starr-Edwards prostheses.

Ninety-six patients were followed for an average of 45 months after insertion of cloth-covered Starr-Edwards prostheses (SE 2300, 2310, 2320, 2400, 6300, 6320, 6400). Operative mortality was 1%, hospital mortality 5.2% and late mortality (45 months) 13.5%. We observed a high incidence of valve disfunction as evidenced by a removal rate of 23% after six years. Disfunction was most reliably detected by abnormal prosthetic sounds and/or murmurs of incompetence at the prostheses. Thromboembolism occurred in 14% of the patients over 6 years and increased hemolysis was found in 18.8% of patients. It is concluded that the low incidence of thromboembolism does probably not out-weight the high incidence of valve disfunction.

Female↗