Analysis of heart rate variability in hypertensive patients before and after treatment with angiotensin II-converting enzyme inhibitors.
OBJECTIVE
To compare heart rate variability in normotensive and hypertensive individuals and to observe the behavior of the autonomic nervous system after treatment with angiotensin II-converting enzyme inhibitors.


METHODS
The study comprised 286 patients diagnosed with arterial hypertension (AH) for the first time and divided into 4 groups according to diastolic blood pressure (DBP) levels: group A -- DBP<90 mmHg; group B -- DBP 90-99 mmHg; group C -- DBP 100-109 mmHg; group D -- DBP>110 mmHg. Group A (110 healthy individuals) and group C (79 patients with moderate AH) underwent 24-hour Holter-ECG with analysis of heart rate variability in time domain (TD) and frequency domain (FD). The group C patients were treated with ACE inhibitors for 3 months, and, after this period, they underwent a new 24-hour Holter-ECG study for assessing heart rate variability, the values being compared with those of normotensive individuals.


RESULTS
The SDNN and PNN50 parameters (TD), and the LF spectrum (FD) were significantly different in the 2 groups, with clearly reduced values in hypertensive individuals (P<0.05). Group C patients, after treatment with ACE inhibitors, showed a recovery in all variables of heart rate variability, achieving values close to those of normotensive individuals.


CONCLUSIONS
Heart rate variability was reduced in hypertensive patients when compared with that in normotensive individuals, indicating a decrease in the baroreceptor reflex. A functional autonomic adjustment after the antihypertensive treatment with ACEI was observed, indicating recovery of parasympathetic tonus.
Universidade Federal de Goiás, Hospital São Francisco de Assis, Goiânia, GO, Brazil.
Antônio da Silva
Ada S
Menezes
Humberto Graner
HG
Moreira
Murilo Tavares
MT
Daher
D000293:Adolescent; D000328:Adult; D000804:Angiotensin II / Q000037:antagonists & inhibitors*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged
D000806:Angiotensin-Converting Enzyme Inhibitors; D000804:Angiotensin II