THE RELATIONSHIP BETWEEN HEART RATE VARIABILITY AND CARDIOVASCULAR RISK FACTORS IN HYPERTENSIVE PATIENTS

Abstract

Objective: Although many cardiovascular risk factors are well known at present, additional number of cardiovascular mortality predictors are needed because of the fact that cardiovascular diseases are also observed in patients who do not have any well described risk factors. The aim of current study is to analyse the relationship between heart rate, heart rate variability and novel cardiovascular risk factors.

Materials and Methods: A total of 63 consecutive patients were included in this study. Aortic pulse wave velocity of all patients was calculated with SphygmoCor (AtCorMedical Instruments) tonometry device. Average heart rate, maximum and minimum heart rate, average RR period, 24 hours triangle index, the mean of the standard deviations for all R-R intervals, standard deviation of all R-R intervals in successive five-minute epochs, and root-mean square differences of successive R-R intervals were obtained by using time dependent heart rate analyse obtained from 24 hours ECG records. 

Results: Mean heart rate of the study population was 84.3±9.2 bpm. Mean pulse wave velocity of the study population was 5.7±0.4 m/sec and mean carotid intima-media thickness of the study population was 0.87±0.09 mm. Patients were classified into two groups according to median night heart rate (≤65 bpm vs. >66 bpm). No significant difference was observed between two groups in terms of age, gender, pulse wave velocity, and cholesterol levels however, a significant difference was observed between groups in terms of carotid intima-media thickness. 

Conclusion: We suggest that heart rate and heart rate variability should be used as a non-invasive method, which can be measured without excessive costs in daily clinical practice.

Keywords

• Heart rate variability,Electrocardiography,Risk of cardiovascular disease

Hipertansif Hastalarda Kalp Hızı Değişkenliği ile Kardiyovasküler Risk Faktörlerinin İlişkisi

Abstract

Amaç: Birçok kardiyovasküler risk faktörünün bilinmesine rağmen, risk faktörleri olmayan hastalarda da kardiyovasküler hastalıkların gözlenmesi nedeniyle yeni bir takım öngördürücülere ihtiyaç duyulmaktadır. Çalışmamızın amacı kalp hızı ve kalp hızı değişkenliğinin yeni geliştirilmiş olan kardiyovasküler risk faktörleri ile ilişkisini değerlendirmektir.

Gereç ve Yöntemler: Çalışmaya toplam 63 ardışık hasta dahil edildi. SphygmoCor (AtCorMedical Instruments) markalı tonometri cihazı ile tüm hastaların aortik nabız dalga hızları hesaplandı. Alınan 24 saatlik elektrokardiyografi kayıtlarından yapılan zaman bağımlı kalp hızı analizlerinde ortalama kalp hızı maksimum ve minimum kalp hızları, ortalama RR süreleri, 24 saat triangle index, the mean of the standard deviations for all R-R intervals, standard deviation of all R-R intervals in successive five-minute epochs ve root-mean square differences of successive R-R intervals değerleri elde edildi. Kalp hızı ve kalp hızı değişkenliği ile yeni geliştirilmiş olan kardiyovasküler risk arasındaki ilişki araştırıldı. 

Bulgular: Çalışma grubunun nabız ortalaması 84.3±9.5 vuru/dk idi. Ortalama sistolik kan basınçları 141.7±13.5 mmHg, diyastolik kan basınçları 75.3±6.9 mmHg, nabız dalga hızı 5.73 ±0.45 m/sn, ortalama karotis intima-media kalınlığı 0.87±0.09 mm idi. Median gecelik kalp hızına (65 vuru/dk) göre 2 gruba ayrılan hastaların yaş, cinsiyet, kolesterol düzeyleri ve nabız dalga hızları arasında anlamlı farklılık saptanmamakla birlikte karotis intima-media kalınlığı ile gecelik kalp hızı arasında anlamlı ilişki saptandı.

Sonuç: Kardiyovasküler hastalığı öngörmede çeşitli girişimsel olmayan tetkikler kullanılmaktadır. Bu tetkiklerin basit olması yanında kardiyovasküler hastalığı tahmin etmede doğruluk oranının da yüksek olması gerekmektedir. Bu açıdan bakıldığında kalp hızı ve kalp hızı değişkenliği günlük klinik kullanımda maliyetsiz ölçülebilen, girişimsel olmayan bir yöntem olarak önem kazanmaktadır ve yakın gelecekte kullanımı umut vadetmektedir.

Keywords

• Kalp Hızı Değişkenliği,Elektrokardiyografi,Kardiyovasküler Hastalık Riski

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