Evaluation of Myocardial Blood Perfusion in Man with Radioactive Potassium or Rubidium and Precordial Counting

Donato, L.; Bartolomei, G; Giordani, Roberto

doi:10.1161/01.cir.29.2.195

Cited by 55 publications

(10 citation statements)

References 11 publications

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“…[16][17][18][19][20] In cases where there is some delay in measuring the potassium activity, there may be uneven losses from the myocardium and the distribution of potassium activity may not represent true distribution of myocardial blood flow. However, the loss of potassium from dog hearts has been shown to be considerably delayed, with approximately 80% of plateau levels remaining at 120 min.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Regional Myocardial Perfusion Determined by Ionic Potassium-43 to That Determined by Microspheres

et al. 1974

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The ability of ionic potassium-43 (43K) to reflect alterations in regional myocardial perfusion was determined by comparing the distribution of this tracer to that of labeled microspheres and flowmeter measurements under several conditions of coronary blood flow. When flow was normal, the regional distribution of ionic 43K and labeled microspheres were similar. In ischemia induced by partial occlusion and pacing, both 43K and microspheres showed the same decrease in activity (0.7 of control). Twenty-six adult mongrel dogs (weight 40-60 lbs) were anesthetized with pentobarbital (30 mg/kg), intubated and maintained on a Harvard pump respirator. A left thoracotomy was performed at the level of the fifth intercostal space and left circumflex coronary artery dissected free. An electromagnetic flow transducer, polyethylene snare (for zeroing), and a fluid-filled balloon occluder were placed around the exposed section of the artery. Both the snare and balloon occluder were positioned distal to the flow transducer. The flow transducer was connected to a Brusch recorder and calibrated with saline prior to positioning on the coronary artery. A polyvinyl catheter was inserted directly into the left atrium for administration of 43K and microspheres.Zero coronary blood flow was obtained by completely occluding the vessel with the polyethylene snare for 10 sec. This maneuver was repeated three times to verify the zero position. Normal resting coronary blood flow was established for 20 min prior to the experimental procedure. The regional distribution of coronary flow as determined by 43K and microspheres was measured at normal resting flow and at 75%, 50%, 25% and 0% of resting flow as measured by the flowmeter. Each dog was examined at only one level of coronary flow. At each coronary flow approximately 400,000 85Sr-labeled carbonized microspheres (diameter 15,u ± 5, density 1.2 to 1.4) and 50O,uCi of 43K in Icc saline were administered in the left atrium. After injection of the tracers, a final flowmeter reading was obtained and the dog

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Section: Discussionmentioning

confidence: 99%

Comparison of Regional Myocardial Perfusion Determined by Ionic Potassium-43 to That Determined by Microspheres

et al. 1974

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“…Other groups of investigators have used radiolabeled Rb' and K+ and precordial detectors to make estimates of "total myocardial flow" in milliliters per minute in the hearts of control subjects and patients with coronary atherosclerosis. Wlhile the data is coInflicting, the majority of workers have reported reductions of total myocardial flow in coronary artery disease (37)(38)(39)(40). This suggests that the reduced myocardial flow/unit mass in twro-and three-vessel disease resulted predominantly from a diminution in coronary blood flow rather than from an increase in the mass of tissue.…”

Section: Regional Myocardial Perfusion and Coronary Arteriographic Lementioning

confidence: 97%

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

Cannon¹,

Schmidt²,

Weiss³

et al. 1975

J. Clin. Invest.

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AB STRA CT Measurements of mean left ventricular (LV) and regional myocardial blood flow rates were made at rest in 161 patients with '=Xe 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. However, mean LV perfusion was significantly reduced in patients with normal coronary arteries who had cardiomyopathy and impaired ventricular performance. Mean LV perfusion was not significantly different from control valtues in patients with "mild" coronary artery disease (< 50% obstruction) or in patients with significant isolated disease (> 50% obstruction) of the left anterior descending (LAD) artery. Significant reductions in mean LV perfusion were found in patients with > 50% obstruction of two coronary arteries (LAD + right or LAD + circumflex) and in patients with triple-vessel disease.The average perfusion rate for regions distal to LAD obstructions in patients with isolated LAD disease was not lower than the LAD perfusion in control patients, but was significantly reduced in patients with LAD + right coronary artery disease (43±14 ml/100 g.min).In the latter group average perfusion distal to the LAD lesion was significantly lower than the average regional perfusion rate for the remainder of the LV. However, The data demonstrate that the presence of radiograplhically "mild" or significant isolated LAD coronary disease is not associated with reductions in mean LV perfusion at rest, but that mean LV perfusion is reduced in the presence of significant disease of two or three coronary arteries. None of the patients experienced angina dturing the resting studies and most had clinical evidence of ventricular failure. The observation of depressed LV perfusion in this group, as in the patients with cardiomvopathy, raises the possibility that a lowered resting blood supply may be adequate for a reduced level of per-formance of a diseased ventricle. The lack of selective reductions of regional perfusion at rest in the majority of the patients with LAD lesions suggests that regional myocardial blood flow must be measured during an intervention which increases myocardial oxygen consumption in order to assess the physiological significance of lesions which are observed at coronary arteriography.

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“…In addition, Donato et al (16) confirmed that CBF in man could be accurately determined on the basis of the fractional distribution of these two tracers. These findings suggest that thallium-201, which is biologically similar to potassium, can be utilized to measure CBF.…”

mentioning

confidence: 93%

Relation between Coronary Blood Flow and Left Ventricular Mass in Hypertension. Noninvasive Quantification of Coronary Blood Flow by Thallium-201 Myocardial Scintigraphy.

et al. 1998

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This study was conducted to quantify coronary blood flow (CBF) noninvasively according to the fractionation principle and to elucidate the relation between CBF and left ventricular hypertrophy. CBF/ cardiac output (CO), estimated on the basis of the ratio of myocardial uptake/total injected dose of thallium-201(% cardiac uptake), was determined in 14 control subjects and 40 patients with essential hypertension. CBF and CBF per 100 g of myocardium (unit CBF) were calculated according to the following formulas: CBF = % cardiac uptake X CO, and unit CBF = (CBF/ LVM) X 100, where CO and left ventricular mass (LVM) are echocardiographically determined. There was good reproducibility of % cardiac uptake (r= 0.983, p < 0.0001). Percent cardiac uptake was greater in hypertensive patients (4.65 ± 1.44%) than in control subjects (3.64± 0.64%), and there was a positive correlation between % cardiac uptake and LVM. CBF (ml/ min) was greater in hypertensive patients (240.7 ± 80.5) than in control subjects (194.9 + 36.9), but unit CBF (ml/min/ 100 g) was less in hypertensive patients (102.2 ± 26.7) than in control subjects (150.3 ± 30.5). Multiple regression analyses showed that LVM was the most potent independent predictor of resting CBF in hypertension. Our results indicate that CBF, determined by thallium-201 myocardial scintigraphy, increases parallel to the increase in LVM, but unit CBF decreases even in the resting condition in patients with essential hypertension. (Hypertens Res 1998; 21: 227-234) Key Words: coronary blood flow, thallium-201 myocardial scintigraphy, left ventricular mass, left ventricular hypertrophy, essential hypertension Left ventricular hypertrophy associated with hypertension is not only a physiological adaptation to sustained arterial hypertension, but also a pathologic process leading to heart failure (1, 2). In addition, left ventricular mass is an independent risk factor for cardiovascular diseases (3, 4), and increased left ventricular mass predicts increased cardiovascular morbidity and mortality (4, 5). However, why left ventricular hypertrophy predisposes patients to morbid events is not fully understood. Many studies have shown that coronary blood flow (CBF) reserve is reduced in hypertensive patients with left ventricular hypertrophy (6-13). Thus, changes in the coronary circulation associated with left ventricular hypertrophy seem to be related to cardiovascular morbidity and mortality. However, only a few studies have quantified CBF in patients with hypertension (6, 7, 12) because of the complexity and invasiveness of conventional techniques for measurement of CBF. CBF can be determined noninvasively by positron-emission tomography with nitrogen-13-ammonia (14), but this method is not in general use. Very recently, Kazakova et al. (13) determined the coronary flow reserve by transesophageal Doppler echocardiography. This method, however, measures only flow velocity and not absolute volumetric flow.Sapirstein (15) first indicated that the fractional distribution of K-42 or Rb-86 co...

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Evaluation of Myocardial Blood Perfusion in Man with Radioactive Potassium or Rubidium and Precordial Counting

Cited by 55 publications

References 11 publications

Comparison of Regional Myocardial Perfusion Determined by Ionic Potassium-43 to That Determined by Microspheres

Comparison of Regional Myocardial Perfusion Determined by Ionic Potassium-43 to That Determined by Microspheres

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

Relation between Coronary Blood Flow and Left Ventricular Mass in Hypertension. Noninvasive Quantification of Coronary Blood Flow by Thallium-201 Myocardial Scintigraphy.

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