Differential heart rate dynamics in transient left ventricular apical and midventricular ballooning.
BACKGROUND
The aim of the present study was to assess potential differences in cardiac autonomic nervous modulation in patients with transient left ventricular apical ballooning syndrome (AB) and the midventricular variant (MB) of this syndrome.


OBJECTIVE
We hypothesized that differences in regional distribution of cardiac autonomic innervation in AB and MB may induce alterations in autonomic modulation, and we tested this assumption by using a combination of traditional and novel nonlinear parameters of heart rate variability (HRV).


METHODS
In a prospective single-center study, 49 consecutive patients with transient left ventricular dysfunction syndrome underwent Holter electrocardiographic recording on the third day after admission. A total of 27 recordings of patients with AB and 10 recordings of patients with MB were valid for analysis of HRV, nonlinear dynamic measures of HRV, detrended fluctuation analysis (DFA), and phase-rectified signal averaging (PRSA).


RESULTS
There were no significant differences in baseline clinical characteristics between AB and MB patients. Patients with MB showed significantly lower values for mean RR interval (835 ± 104 ms vs. 908 ± 118 ms; P < .05), 1/f power law slope (-1.28 ± 0.2 vs. -1.13 ± 0.2; P < .01), and deceleration capacity (DC) (4.6 ± 1.4 ms vs. 6.0 ± 1.4 ms; P < .01), and significantly higher values for low-frequency (LF) spectral component (5.3 ± 0.5 ln ms(2)/Hz vs. 4.8 ± 0.5 ln ms(2)/Hz), LF/high-frequency (HF) (1.7 ± 0.9 ms vs. 1.3 ± 0.6 ms; P < .05), and DFA α1 (1.09 ± 0.1 vs. 0.99 ± 0.1; P < .01) than patients with AB. There were no significant correlations between parameters of HRV, DFA, 1/f power law slope, and PRSA.


CONCLUSIONS
There are significant differences in heart rate dynamics between AB and MB syndromes. Patients with MB show stronger fractal correlations of heart rate dynamics. Thus, inhomogeneous efferent bilateral sympathetic coactivation and differences in reflex autonomic regulation may be underlying pathophysiological mechanisms for AB and MB syndromes.
Bonnemeier
Hendrik
H
Klinik für Innere Medizin III, Kardiologie und Angiologie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel, Germany. hendrik.bonnemeier@uk-sh.de
Demming
Thomas
T
Weidtmann
Britta
B
Ortak
Jasmin
J
Burgdorf
Christof
C
Reppel
Michael
M
Mäuser
Wanda
W
Rosenberg
Mark
M
Frey
Norbert
N
D000368:Aged; D002452:Cell Count; D015716:Electrocardiography, Ambulatory; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D011446:Prospective Studies; D011941:Receptors, Adrenergic; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System / Q000503:physiopathology; D054549:Takotsubo Cardiomyopathy / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
D011941:Receptors, Adrenergic