Circadian blood pressure pattern and cardiac autonomic functions: different aspects of same pathophysiology

Abstract

ÖZETArteriyel kan basıncı sabahın erken saatlerinde zirveye, gece saatlerinde en düşük değerlere ulaşan sirkadiyen bir ritim paterni izlemektedir. Geceleri arteriyel kan basıncındaki düşüş normal sirkadiyen paternin bir parçasıdır. Bu düşüşün görülmediği "non-dipping" olarak adlandırılan sirkadiyen kan basıncı paterni, özellikle hipertansif hastalarda, daha şiddetli hedef organ hasarı ve artmış kardiyovasküler olaylarla birliktedir. Her ne kadar altta yatan mekanizmalar tam olarak bilinmese de "non-dipping" paterni olan kişilerde anormal parasempatik ve sempatik aktiviteleri içeren otonom sistem bozukluğunun olduğu öne sürülmüştür. "Non-dipping" fenomeninde otonom sinir sisteminin rolü birçok çalışmada incelenmiştir. Bu yazıda, sirkadiyen arteriyel kan basıncı paterni ile kardiyak otonomik işlevlerin göstergeleri arasındaki ilişkiyi değerlendiren çalışmaları derlemeyi amaçladık. ( ABSTRACTArterial blood pressure fluctuates with a pattern that follows a circadian rhythm, with a peak in the early morning hours and a trough during nighttime. Nocturnal dipping of arterial blood pressure is part of this normal circadian pattern, and its absence, which is called non-dipping is associated with more severe end-organ damage and increased risk of cardiovascular events, especially in hypertensive patients. Although pathologic mechanisms are still unclear, it has been suggested that non-dippers show impairment in the autonomic system functions that include abnormal parasympathetic and sympathetic activities. Several studies have examined the role of the autonomic nervous system in the non-dipping phenomenon. In this paper, we aimed to review the studies evaluating the relationship between circadian arterial blood pressure pattern and indices of cardiac autonomic functions. (Anadolu Kardiyol Derg 2011; 2: 168-73)

Can Acupuncture Affect the Circadian Rhythm of Blood Pressure? A Randomized, Double-Blind, Controlled Trial

“…22 Among these factors, growing evidence indicates that nondipping is related to an imbalance between the tone of the sympathetic nerve system and that of the parasympathetic nerve system, particularly the failure to shift from sympathetic to parasympathetic activity during sleep. 19,[23][24][25] In general, plasma and urine catecholamines are lower during the night than they are during the day, 26 and direct recordings from the muscle sympathetic nerves have also shown decreased levels of activity during slow-wave, but not rapid eye movement, sleep. Nocturnal dipping (%): [(daytime SBP -nighttime SBP)/daytime SBP)]*100.…”

Inflammation is related to unbalanced cardiac autonomic functions in hypertension: an observational study

“…Several studies have reported decreased HRV among hypertensives (31,32). However, limited data exist about HRT in hypertension.…”

“…Hipertansiyon ile yüksek duyarlıklı C-reaktif protein (hs-CRP), KHD ve KHT arasındaki ilişki yaş ve kreatinin seviyesi gibi karıştırıcı değişkenler için düzeltildikten sonra analiz edildi. Bulgular: Sağlıklı gönüllüler ile karşılaştırıldığında, hastaların hs-CRP değerlerinde artış, KHD parametrelerinde hafif, KHT parametrelerinde ise belirgin bozulma tespit edildi [SDNN; 132±28 karşın 112±34 msn, RMSSD;[27][28][29][30][31][32][33][34][35] …”

“…The association of hypertension with high sensitivity C-reactive protein (hs-CRP), HRV and HRT was analyzed after adjustment for confounding variables as age and creatinine levels. Results: The mean hs-CRP was higher, HRV was slightly reduced while HRT was markedly blunted in hypertensive patients in comparison with control group [SDNN; 132±28 vs. 112±34 msec, RMSSD;[27][28][29][30][31][32][33][34][35] msec, TO; -2.80±2.15 vs. -0.96±2.36%, TS; 7.56 (5.24-10.60) vs. 4.65 (2.44-7.26) msec/RR, p<0.01 for all]. All of the HRV and HRT parameters were more deteriorated in the highest tertile hs-CRP group [SDNN; 93±34 msec, RMSSD; 17 (13-22) msec, TO; 0.03±2.22%, TS; 2.43 (1.84-3.89) msec/RR, p<0.05 for all].…”

Cardiac Autonomic Impairment and Chronotropic Incompetence in Dipper and Nondipper Hypertension

“…3 Nondipper subjects have been reported to have increased cardiovascular morbidity and mortality. [4][5][6] Exercise stress test variables, heart rate recovery (HRR) and chronotropic index (CI), have been shown to have prognostic value. 7 Both an attenuated heart rate (HR) response to exercise (chronotropic incompetence) and HRR after exercise has been considered to reflect cardiac autonomic functions and associated with increased mortality.…”