title: Postextrasystolic potentiation during spontaneous ventricular ectopy in man. Associated left ventricular volume changes determined by list mode radionuclide ventriculography.
abstract: Five patients with spontaneously arising frequent ventricular ectopia were studied by list mode radionuclide ventriculography. Changes in left ventricular volumes reflected the increased inotropy of the postextrasystolic sinus beats: stroke volume increased by +36.0 +/- 32.8% (P less than 0.05) and end-systolic volumes decreasing by 13.6 +/- 7.3% (P less than 0.02) leading to an increased ejection fraction (+31.1 +/- 23.8%; P less than 0.05). There were no significant increases in end-diastolic volumes (+2.2 +/- 5.4%; P:NS). The reproducibility of the left ventricular volume estimates was confirmed by comparing the control sinus beats with the interrupted sinus beats. There were no significant changes in end-diastolic (+1.8 +/- 5.5%), end-systolic (+1.8 +/- 3.7%) and stroke volumes (+5.4 +/- 14.6%). List mode radionuclide ventriculography can be used to accurately monitor left ventricular volume changes associated with spontaneously arising ventricular ectopia. In these patients, the contribution of Frank-Starling mechanism to postextrasystolic potentiation was minimal.
mesh_terms: D000328:Adult; D000368:Aged; D005117:Cardiac Complexes, Premature / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002302:Cardiac Output; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011877:Radionuclide Imaging; D013670:Sodium Pertechnetate Tc 99m; D013318:Stroke Volume
chemical_list: D013670:Sodium Pertechnetate Tc 99m