Analysis of postextrasystolic relaxation response in the human heart.
Postextrasystolic potentiation is the phenomenon in which ventricular contractile force is strengthened by a preceding premature beat. However, the response of diastolic function after an extrasystole is unknown. We studied 58 patients with chronic heart failure (CHF) and two control subjects to evaluate the response of relaxation following extrasystole. At cardiac catheterization, from the derivative of the left ventricular (LV) pressure, the ratio of LV peak negative dP/dt (-dP/dt) of a postextrasystole to a basal beat was calculated and defined as the postextrasystolic relaxation response (PRR). PRR was compared with parameters of left ventriculography: LV end-diastolic volume index (EDVI), LV end-systolic volume index (ESVI), and LV ejection fraction (EF). The PRRs of the two control subjects were 0.80 and 0.84. The mean PRR of the CHF patients was 0.99 +/- 0.15. In all subjects, including patients and controls, correlation analysis between (EDVI, ESVI, and EF) and PRR yielded the following: (a) EDVI vs. PRR: R = 0.273, p = 0.036; (b) ESVI vs. PRR: R = 0.446, p < 0.001; and (c) EF vs. PRR: R = -0.520, p < 0.001. Thus, normal or non-failing human hearts showed a decline of -dP/dt in postextrasystole compared with the basal beats, but failing hearts had potentiated relaxation following an extrasystole.
Kato
Kiminori
K
First Department of Internal Medicine, Niigata University School of Medicine, Niigata, Japan. kkato48@med.niigata-u.ac.jp
Kodama
Makoto
M
Hirono
Satoru
S
Okura
Yuji
Y
Hanawa
Haruo
H
Shiono
Takaaki
T
Ito
Masahiro
M
Fuse
Koichi
K
Tsuchida
Keiichi
K
Maruyama
Seitaro
S
Yoshida
Tsuyoshi
T
Abe
Satoru
S
Hayashi
Manabu
M
Nasuno
Akimitsu
A
Saigawa
Takashi
T
Ozawa
Takuya
T
Aizawa
Yoshifusa
Y
D000328:Adult; D006328:Cardiac Catheterization; D005117:Cardiac Complexes, Premature; D002306:Cardiac Volume; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation; D009200:Myocardial Contraction; D013318:Stroke Volume; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D017725:Ventricular Pressure