P-wave alternans rebound following pulmonary vein isolation predicts atrial arrhythmia recurrence.

INTRODUCTION: Numerous P-wave indices have been explored as biomarkers to assess atrial fibrillation (AF) risk and the impact of therapy with variable success. OBJECTIVE: We investigated the utility of P-wave alternans (PWA) to track the effects of pulmonary vein isolation (PVI) and to predict atrial arrhythmia recurrence. METHODS: This medical records study included patients who underwent PVI for AF ablation at our institution, along with 20 control subjects without AF or overt cardiovascular disease. PWA was assessed using novel artificial intelligence-enabled modified moving average (AI-MMA) algorithms. PWA was monitored from the 12-lead ECG at ~1 h before and ~16 h after PVI (n = 45) and at the 4- to 17-week clinically indicated follow-up visit (n = 30). The arrhythmia follow-up period was 955 ± 112 days. RESULTS: PVI acutely reduced PWA by 48%-63% (p < .05) to control ranges in leads II, III, aVF, the leads with the greatest sensitivity in monitoring PWA. Pre-ablation PWA was ~6 µV and decreased to ~3 µV following ablation. Patients who exhibited a rebound in PWA to pre-ablation levels at 4- to 17-week follow-up (p < .01) experienced recurrent atrial arrhythmias, whereas patients whose PWA remained reduced (p = .85) did not, resulting in a significant difference (p < .001) at follow-up. The AUC for PWA's prediction of first recurrence of atrial arrhythmia was 0.81 (p < .01) with 88% sensitivity and 82% specificity. Kaplan-Meier analysis estimated atrial arrhythmia-free survival (p < .01) with an adjusted hazard ratio of 3.4 (95% CI: 1.47-5.24, p < .02). CONCLUSION: A rebound in PWA to pre-ablation levels detected by AI-MMA in the 12-lead ECG at standard clinical follow-up predicts atrial arrhythmia recurrence.

Individuals with chronic epilepsy have elevated P-wave heterogeneity comparable to patients with atrial fibrillation.

OBJECTIVE: Identification of epilepsy patients with elevated risk for atrial fibrillation (AF) is critical given the heightened morbidity and premature mortality associated with this arrhythmia. Epilepsy is a worldwide health problem affecting nearly 3.4 million people in the United States alone. The potential for increased risk for AF in patients with epilepsy is not well appreciated, despite recent evidence from a national survey of 1.4 million hospitalizations indicating that AF is the most common arrhythmia in people with epilepsy. METHODS: We analyzed inter-lead heterogeneity of P-wave morphology, a marker reflecting arrhythmogenic nonuniformities of activation/conduction in atrial tissue. The study groups consisted of 96 patients with epilepsy and 44 consecutive patients with AF in sinus rhythm before clinically indicated ablation. Individuals without cardiovascular or neurological conditions (n = 77) were also assessed. We calculated P-wave heterogeneity (PWH) by second central moment analysis of simultaneous beats from leads II, III, and aVR ("atrial dedicated leads") from standard 12-lead electrocardiography (ECG) recordings from admission day to the epilepsy monitoring unit (EMU). RESULTS: Female patients composed 62.5%, 59.6%, and 57.1% of the epilepsy, AF, and control subjects, respectively. The AF cohort was older (66 ± 1.1 years) than the epilepsy group (44 ± 1.8 years, p < .001). The level of PWH was greater in the epilepsy group than in the control group (67 ± 2.6 vs. 57 ± 2.5 µV, p = .046) and reached levels observed in AF patients (67 ± 2.6 vs. 68 ± 4.9 µV, p = .99). In multiple linear regression analysis, PWH levels in individuals with epilepsy were mainly correlated with the PR interval and could be related to sympathetic tone. Epilepsy remained associated with PWH after adjustments for cardiac risk factors, age, and sex. SIGNIFICANCE: Patients with chronic epilepsy have increased PWH comparable to levels observed in patients with AF, while being ~20 years younger, suggesting an acceleration in structural change and/or cardiac electrical instability. These observations are consistent with emerging evidence of an "epileptic heart" condition.

Reduction in atrial and ventricular electrical heterogeneity following pulmonary vein isolation in patients with atrial fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) modulates the intrinsic cardiac autonomic nervous system and reduces atrial fibrillation (AF) recurrence. METHODS: In this retrospective analysis, we investigated the impact of PVI on ECG interlead P-wave, R-wave, and T-wave heterogeneity (PWH, RWH, TWH) in 45 patients in sinus rhythm undergoing clinically indicated PVI for AF. We measured PWH as a marker of atrial electrical dispersion and AF susceptibility and RWH and TWH as markers of ventricular arrhythmia risk along with standard ECG measures. RESULTS: PVI acutely (16 ± 8.9 h) reduced PWH by 20.7% (from 31 ± 1.9 to 25 ± 1.6 µV, p < 0.001) and TWH by 27% (from 111 ± 7.8 to 81 ± 6.5 µV, p < 0.001). RWH was unchanged after PVI (p = 0.068). In a subgroup of 20 patients with longer follow-up (mean = 47 ± 3.7 days after PVI), PWH remained low (25 ± 1.7 µV, p = 0.01), but TWH partially returned to the pre-ablation level (to 93 ± 10.2, p = 0.16). In three individuals with early recurrence of atrial arrhythmia in the first 3 months after ablation, PWH increased acutely by 8.5%, while in patients without early recurrence, PWH decreased acutely by 22.3% (p = 0.048). PWH was superior to other contemporary P-wave metrics including P-wave axis, dispersion, and duration in predicting early AF recurrence. CONCLUSION: The rapid time course of decreased PWH and TWH after PVI suggests a beneficial influence likely mediated via ablation of the intrinsic cardiac nervous system. Acute responses of PWH and TWH to PVI suggest a favorable dual effect on atrial and ventricular electrical stability and could be used to track individual patients' electrical heterogeneity profile.

SUDEP - more attention to the heart? A narrative review on molecular autopsy in epilepsy.

Sudden unexpected death in epilepsy (SUDEP) has been identified as one of the most prevalent causes of mortality in epilepsy, and SUDEP has consequently become an important topic of research. The causes appear multifactorial, including epilepsy-induced cardiac arrest. Current understanding of autopsy negative sudden unexplained death (SUD) in general population and its relation to sudden arrhythmic death syndrome (SADS) could shed some light in SUDEP. Mutual attention to the findings of sudden death in cardiology and epilepsy are discussed here. We performed a narrative review on SUDEP, epilepsy and molecular/genetic autopsy in this population. A proposal of an extended terminology for SUDEP classification is discussed in light of recent issues related to molecular autopsy and genetics. The extended classification might be a step forward in research protocols and a tool for better understanding SUDEP.

Left ventricle end-systolic elastance, arterial-effective elastance, and ventricle-arterial coupling in Epilepsy.

OBJECTIVE: Sudden unexpected death in epilepsy (SUDEP) is a tragic event. Cardiac models of sudden death state that, paradoxically, healthy individuals compose most of the victims of this event. Exploration of cardiac physiological variables related to outcome could help unveil risk markers for sudden death in epilepsy. We investigated left ventricle end-systolic elastance, arterial-effective elastance and ventricle-arterial coupling (VAC) in PWE compared with controls. MATERIAL & METHODS: Adult patients with temporal lobe epilepsy without known cardiovascular diseases were submitted to treadmill test and transthoracic echocardiogram. Individuals without epilepsy matched by sex, age, and body mass index composed the control group. Cardiac risk factors, exercise performance, autonomic data from treadmill test, systolic and diastolic function, morphological cardiac data, and left ventricle pressure-volume loop were recorded. RESULTS: Sixty subjects were consecutively enrolled (30 PWE and 30 controls). Epilepsy duration was 22.5 ± 10.7 years (age of onset 15.2 ± 10.1 years). Treadmill variables were significantly worse in TLE patients compared with controls. End-systolic elastance, arterial-effective elastance, and ventricle-arterial coupling were similar between groups. Female sex, percentage of maximal predicted heart rate achieved in exercise, exercise time, and epilepsy duration explained 28,4% of VAC in PWE in multiple stepwise linear regression (P = .018). CONCLUSIONS: Some aspects of the cardiac pressure-volume curves, mainly linked to left ventricle systolic performance, contractile function and their interaction with afterload appears normal in young PWE and cannot explain their increase risk to adverse outcomes or lower physical fitness.

Epilepsy and ultra-structural heart changes: The role of catecholaminergic toxicity and myocardial fibrosis. What can we learn from cardiology?

In this article, we explore the interaction of brain and heart in patients with epilepsy (PWE), focusing on new insights into possible pathways from epilepsy, catecholaminergic toxicity, subtle cardiac changes and sudden death. Initial evidence and biological plausibility point to an interaction between autonomic dysfunction, higher sympathetic drive, myocardial catecholaminergic toxicity and cardiac fibrosis resulting in subtle myocardial changes in structure, function, arrhythmogenesis and/or a heart failure-like phenotype in PWE. Non invasive imaging and biomarkers of cardiac injury and fibrosis are emerging as possible diagnostic tools to better stratify the risk of such individuals. Translational lessons from cardiac models of disease and ultra-structural lesions are used to support these considerations.

Increased cardiac stiffness is associated with autonomic dysfunction in patients with temporal lobe epilepsy.

Autonomic dysfunction is linked to sudden death regardless of the presence of structural heart disease. The pathway from autonomic dysfunction to sudden death is not fully understood, but myocardial sympathetic stimulation leading to arrhythmia and/or cardiac fibrosis might play a role. Our goal was to evaluate cardiac stiffness by echocardiography and its association with clinical, structural, and autonomic variables in people with epilepsy (PWE) compared to healthy controls. A 12-lead electrocardiogram, treadmill testing, and transthoracic echocardiography from 30 patients with temporal lobe epilepsy (TLE) without any known cardiovascular disorders were compared to 30 individuals without epilepsy matched by sex, age, and body mass index. Distribution of cardiovascular risk factors was similar in both groups. PWE had a higher left ventricle stiffness, left ventricle filling pressure, and greater left atrial volume as well as markers of autonomic dysfunction such as impaired chronotropic index and percentage achieved of predicted peak heart rate at effort. In multiple regressions, autonomic dysfunction explained 52% of stiffness and carbamazepine treatment and polytherapy with antiepileptic drugs (AEDs) explained, additionally, 6% each. Stiffness is increased in young patients with TLE and is related to autonomic dysfunction and to a lesser extent, carbamazepine use and polytherapy with AEDs.

Echocardiographic risk markers of sudden death in patients with temporal lobe epilepsy.

Patients with epilepsy (PWE) have an increased risk for sudden unexpected death compared to the general population. Echocardiography can analyze structural and functional heart changes that have impact on outcomes, including sudden cardiac and all-cause death. Our hypothesis is that subtle heart abnormalities occur in PWE. Thirty patients with temporal lobe epilepsy without any known cardiovascular disease, followed for at least 1 year, were enrolled between July 2015 and July 2016 and submitted to a 12-lead electrocardiogram, treadmill test and transthoracic echocardiogram. PWE were matched with individuals without epilepsy by sex, age and body mass index. A literature review of studies comparing echocardiographic findings in PWE and individuals without epilepsy was performed. PWE had a higher left ventricle stiffness (ß= 5.97 ±â€¯0.05 × 5.94 ±â€¯0.03; p = 0.02), left ventricle filling pressures (9.7 ±â€¯1.3 mmHg × 9 ±â€¯0.8; p = 0.02) and a greater left atrial volume (44.7 ±â€¯13.6 ml × 34.1 ±â€¯9.6 ml; p = 0.003). Seventeen (56.6%) PWE had a total of 22 of six known echocardiographic markers related to increased risk for sudden death in the general population, versus 11 (36.7%) controls with 12 markers (p = 0.07). Stiffness is related to fibrosis through extracellular matrix deposition, which promotes systolic and diastolic dysfunction and arrhythmogenesis. Subtle echocardiographic findings in PWE could help to explain why this population has an increased risk to die suddenly.

Maximal/exhaustive treadmill test features in patients with temporal lobe epilepsy: Search for sudden unexpected death biomarkers.

Autonomic dysfunction may account for sudden unexpected death in patients with epilepsy (PWE). On the other hand, low cardiovascular fitness, which may affect autonomic function, is a risk factor for sudden death and all-cause mortality in the general population. Little is known about autonomic variables and cardiovascular response to exercise in PWE. We submitted thirty consecutive PWE with no known cardiovascular diseases to maximal treadmill test, comparing them with matched controls. All individuals were submitted to clinical assessment, 12-lead electrocardiogram (ECG) and echocardiogram to exclude cardiovascular disease. Maximal/exhaustive treadmill test using the Bruce protocol was then performed. Clinical-epidemiological features were similar in both groups, regarding age, sex, body mass index and traditional cardiovascular risk factors. PWE achieved a lower peak heart rate (163.8±21.28bpm×180.9±12.52bpm; p=0.002), lower duration of exercise (673.6±148.27s×784.4±155.72s; p=0.004), lower Duke Score (11.8±2.48×13.4±2.28; p=0.02) and lower achieved metabolic equivalent of task (MET) (12.8±2.49×14.5±2.46; p=0.006). Chronotropic incompetence was more frequent in PWE. Female gender, age of epilepsy onset, number of secondarily generalized seizures and polytherapy were associated to lower cardiovascular fitness in multiple linear regression. Increased risk for SUDEP in PWE may be associated with autonomic disturbances of the cardiovascular system secondary to low cardiovascular fitness.