U.N. Karakulak

Heart rate recovery: a practical clinical indicator of abnormal cardiac autonomic function.

The autonomic nervous system (ANS) and cardiovascular function are intricately and closely related. One of the most frequently used diagnostic and prognostic tools for evaluating cardiovascular function is the exercise stress test. Exercise is associated with increased sympathetic and decreased parasympathetic activity and the period of recovery after maximum exercise is characterized by a combination of sympathetic withdrawal and parasympathetic reactivation, which are the two main arms of the ANS. Heart rate recovery after graded exercise is one of the commonly used techniques that reflects autonomic activity and predicts cardiovascular events and mortality, not only in cardiovascular system disorders, but also in various systemic disorders. In this article, the definition, applications and protocols of heart rate recovery and its value in various diseases, in addition to exercise physiology, the ANS and their relationship, will be discussed.

Predictors of atrial fibrillation recurrence after atrial fibrillation ablation with cryoballoon.

BACKGROUND Catheter ablation of atrial fibrillation is recommended for patients with symptomatic paroxysmal atrial fibrillation (PAF) despite anti-arrhythmic drugs (AADs). Radiofrequency ablation is widely accepted as an effective treatment for PAF. Cryoenergy by cryoballoon technique is an alternative to radiofrequency (RF) ablation. Cryoballoon ablation is safe, and has a similar success rate in comparison to RF ablation. AF recurrence with cryoballoon ablation is roughly 30%. The aim of this study is to determine the predictors of AF recurrence after cryoballoon ablation. METHODS AND RESULTS Sixty one patients with symptomatic PAF despite AADs without structural heart disease were included. Cryoballoon ablation was performed in 60 patients (36 males, mean age: 54.6 ± 10.7, mean left atrium size: 3.74 ± 0.39 mm). Transthoracic echocardiography including tissue Doppler imaging was performed in all subjects during sinus rhythm at baseline and after the ablation. Intra-atrial and inter-atrial electromechanical delays, and PA-lateral were measured. All patients were scheduled for 24 h Holter recording at baseline and at 3, 6, 9 months follow-up. Venous samples were collected to measure CK-MB, Troponin-T (TnT), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels at baseline and 24 h after ablation. Median follow up was 10 (8-12) months. Forty eight (80%) patients were in sinus rhythm during the follow up. In receiver operating curve (ROC) analysis, intraleft atrial electromechanical delay and PA-lateral achieve an area under the curve (AUC) 0.97 (p < 0.001) and 0.69 (p < 0.001) for the ability to predict AF recurrence. A cut-off value for baseline intra left atrial electromechanical delay of 29.5 ms predicted AF recurrence with sensitivity of 85% and specifity of 98%. A cut-off value for PA-lateral of 125 ms predicted AF recurrence with sensitivity of 80% and specifity of 90%. In ROC analysis, age achieves an AUC 0.822 (p = 0.006) for the ability to predict AF recurrence. A cut-off value for age of 64 predicted AF recurrence with sensitivity of 71% and specifity of 90%. Early recurrence of AF (HR = 60, 95% CI 18.61-417.86, p < 0.001) predicted also late recurrence of AF. CONCLUSIONS The increase in AF recurrence by increased intraleft atrial electromechanical delay, PA-lateral and older age show the importance of substrate in AF mechanism. Early recurrence was the strongest predictor of late recurrence of AF; therefore, existence of blanking period for cryoballoon ablation should be questioned.

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

Arterial 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.

Cardiac resynchronization therapy improves exercise heart rate recovery in patients with heart failure.

AIMS Heart rate (HR) recovery (HRR), defined as the rate of decline in the HR immediately following the cessation of exercise, is influenced by autonomic function. Heart rate recovery in heart failure (HF) has been shown to correlate with severity of HF. Cardiac resynchronization therapy (CRT) improves cardiac autonomic functions in HF. We aimed to evaluate the effects of CRT on cardiac autonomic function assessed by HRR. METHODS AND RESULTS Forty-eight patients [62.3 ± 10.7 years; 37 men; left ventricular (LV) ejection fraction 24.8 ± 4.1%] with HF were enrolled. A treadmill exercise testing was conducted in all patients by using a modified Naughton protocol before and 6 months after CRT. Heart rate recovery indices were calculated by subtracting first, second, and third minute HR from the maximal HR and designated as HRR1, HRR2, and HRR3, respectively. Standard echocardiography was performed before and 6 months after CRT. Left ventricular reverse remodelling (LVRM) was quantified as the percentage of decline in the LV end-systolic volume after CRT. Mean HRR1 (13.0 ± 5.9 vs. 17.9 ± 8.9 b.p.m., P = 0.001), HRR2 (20.5 ± 9.3 vs. 23.8 ± 11.3 b.p.m., P = 0.001), and HRR3 (25.7 ± 11.1 vs. 29.2 ± 12.0 b.p.m., P = 0.001) values improved 6 months after CRT. Pearsons analyses revealed a good positive correlation between LVRM and ΔHRR1 (r = 0.642, P = 0.001) and a moderate correlation between reduction LVRM and ΔHRR2 (r = 0.591, P = 0.033) and ΔHRR3 (r = 0.436, P = 0.001). CONCLUSION Cardiac resynchronization therapy favourably alters the cardiac autonomic functions. Heart rate recovery indices improved after CRT and the degree of improvement in HRR indices correlated with LVRM.

Multimodality imaging of coronary-subclavian-vertebral steal syndrome.

A 59-year-old man was admitted with unresolved chest pain after coronary artery bypass graft surgery that had been performed 3 years earlier; aorta-obtuse marginalis, and aorta-posterior descending artery with the use of a saphenous vein graft and left anterior descending artery-left internal mammary artery (LIMA). He reported recurrent angina pectoris and cerebral symptoms, including dizziness and drop attacks, especially when moving his left arm. When he stopped moving his left upper extremity, these symptoms were spontaneously resolved within minutes. On physical examination, pulse rate was regular at 72 beats/min, and there was a significant blood pressure difference between the right and the left arm (135/85 mm Hg and 95/65 mm Hg, respectively). On auscultation, there was a marked bruit at the left supraclavicular region. The results of transthoracic echocardiography were within normal limits. We performed coronary computed tomography angiography to display the cause of ischemic symptoms. Coronary computed tomography angiography revealed that the left subclavian artery was totally occluded 2 cm from its …

Frequency and predictors of renal artery stenosis in hypertensive patients undergoing coronary angiography.

Renal artery stenosis (RAS) and coronary artery disease share common risk factors. We investigated the frequency and predictors of RAS among hypertensive patients who underwent elective coronary angiography. A total of 832 hypertensive patients underwent coronary and renal angiography at the same session. Renal artery stenosis was classified as mild, moderate, or severe. The study population consisted of 4 groups; 71.1% with normal renal arteries, 12.5% with mild, 8.9% with moderate, and 7.5% with severe RAS. The prevalence of significant (≥50%) RAS was 16.3%. The Gensini score showed a stepwise rise with increasing severity of RAS. Age, duration of hypertension, estimated glomerular filtration rate, Gensini score, and multivessel disease were independent predictors for the presence of RAS. Hypertensive patients with those risk factors might need detailed investigation for RAS which may affect their prognosis.

Prolonged Tp-e interval and Tp-e/QT correlates well with modified Rodnan skin severity score in patients with systemic sclerosis

BACKGROUND Ventricular arrhythmias can be seen in systemic sclerosis (SSc) patients and are thought to be a result of fibrosis or ischemia of the ventricular myocardium. Tp-e interval and Tp-e/QT ratio are electrocardiographic (ECG) indices to predict ventricular tachyarrhythmia and cardiovascular mortality. We aimed to evaluate Tp-e interval and Tp-e/QT ratio in patients with SSc. METHODS A total of 107 patients with SSc (mean age, 48.6 ± 14.0 years; 96 females) and 100 healthy controls (mean age, 49.4 ± 8.6 years; 90 females) were enrolled. The standard 12-lead ECG was recorded; QTc, Tp-e interval and Tp-e/QT ratio were measured. Modified Rodnan skin severity score (MR-SSS) calculated for all SSc patients. RESULTS Tp-e interval (90.7 ± 23.8 ms vs. 84.0 ± 20.6 ms, p = 0.032) and Tp-e/QT ratio (0.20 ± 0.05 vs. 0.18 ± 0.04, p = 0.007, respectively) were significantly prolonged in SSc patients than in the control group. Pearsons correlation analyses revealed positive correlations of MR-SSS with QTc (r = 0.427, p = 0.001), Tp-e interval (r = 0.620, p = 0.001) and Tp-e/ /QT ratio (r = 0.615, p = 0.001). MR-SSS (b = 2.108, p = 0.001) and CRP (b = 2.273, p = 0.027) were found to be significant independent predictors of Tp-e interval. Similarly, MR-SSS (b = 0.004, p = 0.001) was only a significant independent predictor of Tp-e/QT ratio among patients with SSc. CONCLUSIONS The patients with SSc had a prolonged Tp-e interval and Tp-e/QT ratio compared with normal subjects. Furthermore, this prolongation was well correlated with clinical severity score among patients with SSc. Ventricular repolarization dispersion as a predictor of ventricular arrhythmias was found to be diminished in patients with SSc. Patients with SSc, particularly with higher MR-SSS, should be followed closely for adverse cardiovascular outcomes.

Assessment of cardiac autonomic nervous system involvement in systemic sclerosis via exercise heart rate recovery.

Objective: To assess exercise heart rate recovery (HRR) indices in patients with systemic sclerosis (SSc) for an assessment of their cardiac autonomic function. Subjects and Methods: Thirty-five patients with diffuse or limited SSc and 35 healthy controls were enrolled. All subjects underwent exercise testing and transthoracic echocardiography. The HRR indices were calculated by subtracting the first- (HRR1), second- (HRR2) and third-minute (HRR3) heart rates from the maximal heart rate. Results: The SSc and control groups were similar in age (45.2 ± 11.6 vs. 43.9 ± 10.0 years), had identical gender ratios (31 female/4 male in both groups) and similar left ventricular ejection fraction (66.5 ± 5.1 vs. 67.7 ± 5.9%). The mean HRR1 (21.8 ± 4.4 vs. 27.7 ± 4.3 bpm, p = 0.001), HRR2 (43.8 ± 6.3 vs. 47.6 ± 4.4 bpm, p = 0.004) and HRR3 (58.8 ± 10.3 vs. 63.6 ± 7.3 bpm, p = 0.031) values were significantly lower in the SSc group than in the healthy controls. HRR indices were similar in the limited and diffuse SSc subgroups. Conclusions: The patients with SSc had lower HRR indices than normal subjects. Cardiac autonomic functions might be involved in SSc, even in patients without cardiac symptoms.

Evaluation of the ambulatory arterial stiffness index in patients with rheumatoid arthritis.

ObjectivePatients with rheumatoid arthritis (RA) are at a higher risk of arterial disease, endothelial dysfunction, and vascular inflammation than the general population. Therefore, these patients are prone to decreased arterial compliance and increased arterial stiffness. Ambulatory arterial stiffness index (AASI) was introduced as an index that predicts cardiovascular risk. In this study, the AASI was evaluated in RA patients. MethodThirty-three RA patients and 33 healthy age-matched and sex-matched individuals were evaluated according to the 24 h blood pressure (BP) profiles. The regression slope of diastolic over systolic BP was computed for each participant. AASI was defined as 1− regression slope. ResultsThere was no significant difference in terms of the basic demographic characteristics, and average day, average night, and total average BP profiles as well as dipper status among the two groups. AASI was 0.45±0.12 and 0.38±0.10 in the RA patients and the healthy controls, respectively (P=0.019). AASI was not significantly different in women and men in both the groups. AASI was significantly higher in nondippers compared with dippers in the entire group and the RA group, but not in the control group. Independent predictors that were found to affect AASI in RA patients were age, nondipper status, VAS score, DAS28 score, and rheumatoid factor positivity. ConclusionAASI is higher in RA patients compared with healthy individuals. When the prognostic significance of AASI is considered, RA patients with higher AASI should be followed closely for future adverse cardiovascular outcomes.

The relationship between circadian blood pressure pattern and ventricular repolarization dynamics assessed by QT dynamicity.

ObjectiveThe aim of the present cross-sectional study was to evaluate ventricular repolarization dynamics by QT dynamicity in normotensive and hypertensive individuals with either a non-dipper-type or a dipper-type circadian rhythm of blood pressure (BP). MethodsA total of 103 patients were allocated into four groups as follows: (i) normotensive/dipper, n=28; (ii) normotensive/nondipper, n=26; (iii) hypertensive/dipper, n=25; and (iv) hypertensive/nondipper, n=24. The linear regression slopes of the QT interval measured to the apex and to the end of the T wave plotted against R–R intervals (QTapex/R–R and QTend/R–R slopes, respectively) were calculated from 24-h ambulatory ECG recordings using a dedicated algorithm. ResultsQTapex/R–R and QTend/R–R slopes were higher in the nondipper subgroup of normotensive cases with respect to the dipper subgroup of normotensive cases (QTapex/R–R=0.171±0.017 vs. 0.127±0.023, P=0.001; QTend/R–R=0.159±0.015 vs. 0.133±0.025, P=0.001). QTapex/R–R and QTend/R–R slopes were higher in the nondipper subgroup of hypertensive cases with respect to the dipper subgroup of hypertensive cases (QTapex/R–R=0.187±0.019 vs. 0.133±0.019, P=0.001; QTend/R–R=0.183±0.018 vs. 0.147±0.022, P=0.001). Pearsons correlation analyses revealed a higher negative correlation between night-time decline in BP and QTapex/R–R (r=−0.638, P=0.001). There was also a moderate negative correlation between night-time decline in BP and QTend/R–R (r=−0.504, P=0.001). The correlation coefficients for degree of night-time dipping and QT dynamicity indices were higher in hypertensive groups than in the normotensive groups. ConclusionBlunting of the nocturnal fall in BP associates with impaired QT dynamicity indices in both normotensive and hypertensive groups.