Influence of parasympathetic modulation in doppler mitral inflow velocity in individuals without heart disease.
BACKGROUND
The relation between left ventricular filing velocities determined by Doppler echocardiography and autonomic nervous system function assessed by heart rate variability (HRV) is unclear. The aim of this study was to evaluate the influence of the autonomic nervous system assessed by the time and frequency domain indices of HRV in the Doppler indices of left ventricular diastolic filling velocities in patients without heart disease.


METHODS
We studied 451 healthy individuals (255 female [56.4%]) with normal blood pressure, electrocardiogram, chest x-ray, and treadmill electrocardiographic exercise stress test results, with a mean age of 43+/-12 (range 15-82) years, who underwent transthoracic Doppler echocardiography and 24-hour electrocardiographic ambulatory monitoring. We studied indices of HRV on time (standard deviation [SD] of all normal sinus RR intervals during 24 hours, SD of averaged normal sinus RR intervals for all 5-minute segments, mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals>50 ms) and frequency (low frequency, high frequency, very low frequency, low frequency/high frequency ratio) domains relative to peak flow velocity during rapid passive filling phase (E), atrial contraction (A), E/A ratio, E-wave deceleration time, and isovolumic relaxation time. Statistical analysis was performed with Pearson correlation and logistic regression.


RESULTS
Peak flow velocity during rapid passive filling phase (E) and atrial contraction (A), E/A ratio, and deceleration time of early mitral inflow did not demonstrate a significant correlation with indices of HRV in time and frequency domain. We found that the E/A ratio was<1 in 45 individuals (10%). Individuals with an E/A ratio<1 had lower indices of HRV in frequency domain (except low frequency/high frequency) and lower indices of the mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals>50 ms in time domain. Logistic regression demonstrated that an E/A ratio<1 was associated with lower HF.


CONCLUSIONS
Individuals with no evidence of heart disease and an E/A ratio<1 demonstrated a significant decrease in indexes of HRV associated with parasympathetic modulation.
Antelmi
Ivana
I
Heart Institute (Incor), University of São Paulo Medical School, São Paulo, Brazil.
Yamada
Alice Tatsuko
AT
Hsin
Chang Nan
CN
TsuTsui
Jeane M
JM
Grupi
Cesar José
CJ
Mansur
Alfredo José
AJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D015716:Electrocardiography, Ambulatory / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000294:innervation*; D006331:Heart Diseases; D006339:Heart Rate / Q000502:physiology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000502:physiology; D011379:Prognosis; D012016:Reference Values; D055815:Young Adult