Regional myocardial perfusion during atrial pacing in patients with coronary artery disease.

Regional myocardial perfusion (RMP) was measured with 133xenon and a multiple-crystal scintillation camera at rest and during atrial pacing in 24 patients with normal coronary arteriograms or less than 50% lesions, Group I, and in 24 with significant (greater than 50% lesions) left coronary artery disease (CAD), Group II. Pacing induced increases in the double product (DP) of heart rate and systolic blood pressure, an index of myocardial oxygen consumption, were not different for Groups I and II. In Group I average mean LV perfusion rate was subnormal at rest but rose from 49 to 73 ml/100 g-min during pacing to 150/min without angina.

Nonhormonal chemotherapy for disseminated renal cell carcinoma.

Twenty-five patients with disseminated renal cell carcinoma have been followed for eleven months. These patients have been treated with CCNU, bleomycin, methotrexate, and platinum in various combinations. The results have been discussed in light of other studies using chemotherapeutic agents against this disease process.

The relationship between regional myocardial perfusion at rest and arteriographic lesions in patients with coronary atherosclerosis.

Measurements of mean left ventricular (LV) and regional myocardial blood flow rates were made at rest in 161 patients with 133Xe and a multiplecrystal scintillation camera. Myocardial perfusion rates were correlated with assessments of the degree of coronary artery disease made from the arteriograms obtained during the same studies. In patients with normal coronary arteries without heart failure, the presence of hypertension, aortic stenosis, or aortic insufficiency was not associated with changes in mean LV perfusion from the control value of 61+/-7 ml/100 g-min.

Measurement of regional myocardial blood flow in man: description and critique of the method using xenon-133 and a scintillation camera.

A method has been devised to measure regional myocardial blood flow in man. The approach consists of selective injection of xenon-133 into a coronary artery and the external monitoring of radioisotope washout curves from multiple areas of the myocardium with a multiple crystal scintillation camera. Rate constants of isotope washout are calculated using a monoexponential model, and the capillary blood flow rates in multiple regions of the heart are calculated by the Kety formula.

Volume ejected in early systole. A sensitive index of left ventricular performance in coronary artery disease.

Indices based on early systolic ejection rates are theoretically more sensitive to ventricular performance than indices based on the entire systolic ejection (SE) period (mean ejection phase indices-MEPI): mean systolic ejection rate (MSER), mean normalized systolic ejection rate (MNSER) and mean velocity of circumferential fiber shortening (MVcf). The volume ejected in early systole is an indicator of the early rate of ejection. Accordingly, ventricular volume changes were determined by ventriculographic analysis for each thrid of SE in ml/sec (SER), as normalized systolic ejection rate (NSER), and as percent of stroke volume (PSV).

Studies of regional myocardial perfusion in patients with coronary atherosclerosis, using xenon-133 and a multiple crystal scintillation camera.

Regional myocardial perfusion was measured in 164 patients at coronary arteriography. Washout of xenon-133 from multiple areas of the heart was monitored with a multiple crystal scintoooillation camera after tracer injection int the left or right coronary artery. Rate constants of radioisotope clearance were computed by monoexponential analysis of the initial portion of each washout curve.

Regional myocardial perfusion rates in patient with coronary artery disease.

Regional myocardial perfusion rates were estimated from the myocardial washout of (133)Xenon in 24 patients with heart disease whose coronary arteriograms were abnormal and 17 similar subjects whose coronary arteriograms were judged to be normal. Disappearance rates of (133)Xe from multiple areas of the heart were monitored externally with a multiple-crystal scintillation camera after the isotope had been injected into a coronary artery and local myocardial perfusion rates were calculated by the Kety formula. The mean myocardial perfusion rates in the left ventricle exceeded those in the right ventricle or atrial regions in subjects without demonstrable coronary artery disease.

Measurement of regional myocardial perfusion in man with 133 xenon and a scintillation camera.

A method was devised to quantitate regional capillary perfusion in the human heart by measuring the clearance constants (k) of Xenon-133 washout from multiple areas of the myocardium with a multiple-crystal scintillation camera. In 17 subjects, (133)Xe was injected into the right or left coronary artery or both and counts per second (cps) were recorded simultaneously on magnetic tape from each of 294 scintillation crystals viewing the precordium through a multichannel collimator. Data were processed by a digital computer.