Arrhythmic Risk in Elderly Patients Candidates to Transcatheter Aortic Valve Replacement: Predictive Role of Repolarization Temporal Dispersion

Abstract

Background/Aim Degenerative aortic valve stenosis (AS) is associated to ventricular arrhythmias and sudden cardiac death, as well as mental stress in specific patients. In such a context, substrate, autonomic imbalance as well as repolarization dispersion abnormalities play an undoubted role. Aim of the study was to evaluate the increase of premature ventricular contractions (PVC) and complex ventricular arrhythmias during mental stress in elderly patients candidate to the transcatheter aortic valve replacement (TAVR). Methods In eighty-one elderly patients with AS we calculated several short-period RR- and QT-derived variables at rest, during controlled breathing and during mild mental stress, the latter being represented by a mini-mental state evaluation (MMSE). Results All the myocardial repolarization dispersion markers worsened during mental stress ( p < 0.05). Furthermore, during MMSE, low frequency component of the RR variability increased significantly both as absolute power (LF RR ) and normalized units (LF RRN U ) ( p < 0.05) as well as the low-high frequency ratio (LF RR /HF RR ) ( p < 0.05). Eventually, twenty-four (30%) and twelve (15%) patients increased significantly PVC and, respectively, complex ventricular arrhythmias during the MMSE administration. At multivariate logistic regression analysis, the standard deviation of QTend (QTe sd ), obtained at rest, was predictive of increased PVC (odd ratio: 1.54, 95% CI 1.14–2.08; p = 0.005) and complex ventricular arrhythmias (odd ratio: 2.31, 95% CI 1.40–3.83; p = 0.001) during MMSE. The QTe sd showed the widest sensitive-specificity area under the curve for the increase of PVC (AUC: 0.699, 95% CI: 0.576–0.822, p < 0.05) and complex ventricular arrhythmias (AUC: 0.801, 95% CI: 0.648–0.954, p < 0.05). Conclusion In elderly with AS ventricular arrhythmias worsened during a simple cognitive assessment, this events being a possible further burden on the outcome of TAVR. QTe sd might be useful to identify those patients with the highest risk of ventricular arrhythmias. Whether the TAVR could led to a QTe sd reduction and, hence, to a reduction of the arrhythmic burden in this setting of patients is worthy to be investigated.

Time‐ and frequency‐domain analysis of repolarization phase during recovery from exercise in healthy subjects

“…Notably, these preliminary results are extremely interesting in their applicability in the clinical and research fields. Rapid identification of noninvasive electrocardiographic markers’ modifications could demonstrate highly useful in emergency settings or during evaluation of patients, candidates to specific procedures 2 . In particular, these findings could be aimed at the highlighting and predicting the possible occurrence of potentially malignant arrhythmias among fragile subjects.…”

“…From the research point of view, the present study lays the physiological foundations that must be verified in specific pathological contexts (acute myocardial infarction, chronic exacerbated heart failure, etc.) in which an increase in the activity of the sympathetic autonomic nervous system is widely demonstrated 2,17,18 …”

“…To calculate repolarization variables a template method has been used 17 . We designed and produced a software for data acquisition, storage, and analysis with the LabView program (National Instruments), which applies the technical recommendation of consensus guidance endorsed by European Heart Rhythm Association jointly with the European Society of Cardiology Working Group on cardiac cellular electrophysiology, as described in detail in previous papers 1,2,8‐13,18,19 …”

“…Although the temporal dispersion markers of myocardial repolarization phase are rarely used in daily clinical practice, they are known to enhance the sudden cardiac death risk evaluation as well as the chronic heart failure management 1,2 . However, up to now, little is known about the effect of autonomic nervous system on temporal myocardial repolarization dispersion in healthy subjects 3 …”

Short-Period Temporal Dispersion Repolarization Markers Predict 30-Days Mortality in Decompensated Heart Failure

“…Of note, besides the direct myocardial structural damages (i.e., ischemia, necrosis, fibrosis, hypertrophy, disarray, etc.) [ 5 , 6 ], drugs [ 7 , 8 , 9 ], aging [ 9 , 10 , 11 , 12 ], mental stress [ 13 , 14 , 15 ] and neurohumoral activation [ 4 , 10 , 12 , 16 , 17 , 18 , 19 , 20 , 21 ], as well as the immune–inflammatory response [ 22 , 23 ] are all factors able to worsen the myocardial repolarization phase. Thus, due to the abovementioned high susceptibility to different possible stressors, there is growing interest in the analysis of myocardial repolarization phase dispersion as a possible marker of global cardiovascular risk rather than a mere non-invasive electrophysiological marker of electrical instability.…”