The Roles of Pre-P-wave Versus Peri-P-wave Fractionated Electrograms for Atrial Substrate Beyond Entrainment Response.

Atrial tachycardia (AT) with alternating cycle lengths is sparsely reported, and, hence, the ideal mapping strategy has not been firmly established. Beyond the entrainment during tachycardia, some fragmentation characteristics might also give important clues for its possible participation in the macro-re-entrant circuit. We discuss a patient with prior atrial septal defect surgical closures who presented with dual macro-re-entrant ATs related to a fragmented area on the right atrial free wall (240 ms) and the cavotricuspid isthmus (260 ms), respectively. After ablation of the fastest AT on the lateral right atrial free wall, the cycle of the first AT changed to the second AT that was interrupted on cavotricuspid isthmus, proving the dual tachycardia mechanism. This case report addresses the utilization of electroanatomic mapping information as well as fractionated electrogram timing with respect to the surface P-wave as guides for ablation location.

The Initial Part of Polymorphic Ventricular Tachycardia as a Clue for the Sustainability of Tachycardia and Ablation Success: A Varying Degree of Purkinje-Myocardial Complicity?

The cardiac Purkinje system is capable of very rapid burst activity suggestive of its potential role in being a driver of polymorphic ventricular tachycardia (VT) (PMVT) or ventricular fibrillation (VF). It plays a pivotal role, however, not only in the triggering of but also the perpetuation of ventricular arrhythmias. A varying degree of Purkinje-myocardial complicity has been blamed in determining not only the sustained or non-sustained nature of PMVT but also the pleomorphism of the non-sustained runs. The initial part of PMVT before cascading to the whole ventricle to establish disorganized VF can give important clues for ablation of PMVT and VF. We present a case of an electrical storm after acute myocardial infarction that was successfully ablated after identifying Purkinje potentials that triggered polymorphic, monomorphic, and pleiomorphic VTs and VF.

Atrial Tachycardia with Cycle Length Alternans.

Tachycardia-induced tachycardia, or so-called double tachycardia, appears to be a relatively rare condition. The underlying mechanism for stable beat-to-beat cycle length variability (alternans) in atrial tachycardia has been sparsely reported.

Convergent Double Coronary Sinus Potentials During Atrial Tachycardia.

The analysis of the patterns and timing of coronary sinus activation provides a rapid stratification of the most likely macro-re-entrant atrial tachycardias and points toward the likely origin of centrifugal ones by comparing the left atrial and coronary sinus activation sequence and morphology during sinus rhythm and atrial tachycardia. The analysis of both the near- and far-field electrogram morphology of atrial signals also gives important clues in determining the mechanism of the arrhythmia.

Electrocardiography clues in assessment of patients with premature ventricular contractions

Background/aim: Some electrocardiography (ECG) parameters such as Tp-e interval, Tp-e / QT ratio, fragmented QRS (fQRS), and heart rate variability (HRV) are related to cardiovascular mortality and morbidity. We aim to investigate the relation between premature ventricular contraction burden and these parameters on 24-h ECG recording. Materials and methods: The study is a retrospective investigation of the 24-h Holter ECG and echocardiography of 199 patients who underwent the procedures due to complaints of palpitation. A frequency of < 10% PVCs / 24 h was classified as seldom group (98 patients), while > 10% PVCs / 24 h was designated as frequent group (101 patients). Results: Tp-e interval was significantly longer (62 [54­78] vs 75 [60­84], p < 0.001), Tp-e / QT ratio was significantly increased (0.18 [0.16­0.20] vs 0.21 [0.18­0.22], p = 0.001) in frequent PVC group. The percentage of fQRS was significantly increased in frequent PVC group (30.6% vs 47.5%, p = 0.015). When the groups were compared, no significant difference was found in HRV time domain indices. Positive correlations were observed between PVC burden and Tp-e (r = 0.304, p < 0.001), Tp-e / QT (r = 0.275, p < 0.001). Conclusion: Our study showed that Tp-e interval, Tp-e / QT and fQRS are associated with frequency of PVCs. These measurements in patients with PVCs may form part of assessment of cardiovascular risk.

Cardiac involvement in MRI in young population after COVID-19: A single tertiary center experience.

BACKGROUND: Coronavirus 2019 (COVID-19) causes morbidity and mortality in an increasing number of people worldwide. Although it mainly affects the respiratory system, it influences all organs, including the heart. It is associated with a broad spectrum of widespread cardiovascular problems ranging from mild myocardial injury to fulminant myocarditis. We aimed to evaluate the presence and prevalence of cardiac involvement in asymptomatic or symptomatic patients after they recovered from COVID 19 infection. METHODS: A total of 100 consecutive patients with COVID-19 proven by reverse transcription polymerase chain reaction (RT-PCR), under 40 years of age and without any known additional chronic diseases were analyzed retrospectively for cardiac magnetic resonance (CMR) results and symptoms. RESULTS: Cardiac involvement was detected in 49 out of 100 patients on CMR imaging. In the cardiac involvement group, the number of patients with chest pain and/or dyspnea was 41 (84%), which was statistically significant (p = 0.001). Twenty-four patients (47%) in the without cardiac involvement group were asymptomatic and this was also statistically significant (p = 0.001). LV ejection fraction was statistically significantly lower in the group with cardiac involvement (61% vs 66%, p = 0.001). LV stroke volume and tricuspid annular plane systolic excursion (TAPSE) were statistically significantly lower in patients with cardiac involvement (p = 0.028 and p = 0.019, respectively). CONCLUSION: Based on single center experience, myocardial involvement is common in symptomatic patients after COVID-19. More studies are needed for long-term side effects and clinical results in these patients.

The prognostic role of cardiac troponin in hospitalized COVID-19 patients.

BACKGROUND AND AIMS: Myocardial injury defined by elevation of cardiac troponins (cTn) in the course of coronavirus disease 2019 (COVID-19) pandemic has been reported, though not fully characterized yet. Using the Turkish nationwide centralized COVID-19 database, we sought to determine whether cTn measured within 24 h of admission may help identify 30-day all-cause mortality in hospitalized patients. METHODS: This retrospective cohort study was conducted at all hospitals in Turkey between March 11, 2020, and June 22, 2020. All hospitalized COVID-19 patients (≥18 years) who had cTn measurements within 24 h of admission were included. The primary outcome was 30-day all-cause mortality. RESULTS: A total of 14,855 COVID-19 patients (median age 49 years and 54% male) from 81 provinces of Turkey were included. Of these, 2020 patients (13.6%) were transferred to intensive care unit, 1165 patients (7.8%) needed mechanical ventilation, and 882 patients (5.9%) died during hospitalization. The prevalence of cTn positivity was 6.9% (n = 1027) in the hospitalized patients. cTn positivity was 5% in those patients alive at 30-day, and 44% in those who died. In multivariable Cox proportional hazard regression model, age, lactate dehydrogenase, and cTn were the strongest predictors of 30-day mortality, irrespective of cTn definition as a continuous, ordinal variable, or dichotomic variables. CONCLUSIONS: A single measurement of cTn at admission in patients with COVID-19 is associated with 30-day all-cause mortality and may have an important prognostic role for optimizing risk stratification.

Coronary Sinus Diameter to Inferior Vena Cava Diameter Ratio in the Diagnosis of Cardiac Tamponade: A Novel Approach.

BACKGROUND: In cardiac tamponade, coronary sinus (CS) as an intrapericardial structure can be easily compressed, whereas inferior vena cava (IVC) dilates. This inverse relationship may augment their roles in the evaluation of tamponade imaging. AIM: We assessed the usefulness of computerized tomographic measures of CS diameter and also CS/IVC ratio to predict tamponade in clinically stable patients with large pericardial effusion. METHODS: Sixty-six clinically stable patients who had large pericardial effusions were included. Coronary sinus diameter was measured from the point at 1 cm proximal to the CS ostium. Inferior vena cava diameter was measured from the segment between its right atrial orifice and hepatic vein. RESULTS: Patients with tamponade had smaller CS diameter and CS/IVC ratio. After adjusting with other parameters, only either CS diameter or CS/IVC ratio predicted tamponade, respectively. (Nagelkerke r value for CS was 53.7% and 72.1% for CS/IVC ratio). In Receiver Operating Characteristic Curve analysis, a cutoff value of 6.85 mm for CS diameter had 82.6% sensitivity and 83.7% specificity and a cutoff value of 27% for CS/IVC ratio had 87.0% sensitivity and 86.0% specificity for predicting cardiac tamponade. CONCLUSIONS: The tomographic measures of both the CS diameter and the CS/IVC ratio predicted tamponade in clinically stable patients with large pericardial effusion. Compared with CS diameter, CS/IVC ratio seemed to be a more powerful predictor of tamponade.

Usefulness of positive T wave in lead aVR in predicting arrhythmic events and mortality in patients with hypertrophic cardiomyopathy.

BACKGROUND: Positive T wave in lead aVR (TaVR) has been associated with increased risk of adverse events in patients with various cardiovascular diseases. OBJECTIVE: The purpose of this study was to investigate the prevalence and prognostic significance of positive TaVR in patients with hypertrophic cardiomyopathy (HCM). METHODS: This study investigated 421 consecutive patients with HCM (177 women; age 51.1 ± 14.9 years). Admission electrocardiogram was examined for the presence of a positive TaVR. The primary endpoint was defined as a composite of major arrhythmic events (MAEs), which included sudden cardiac death, sustained ventricular tachycardia or fibrillation, or appropriate implantable cardioverter-defibrillator therapy. Cardiovascular mortality and all-cause death were evaluated as secondary endpoints. RESULTS: During median follow-up period of 6.0 years (interquartile range 4.0-11.6 years), 53 patients (12.6%) experienced the primary endpoint. On multivariable competing analysis, after adjusting for other confounding factors, the presence of positive TaVR was found to be an independent and strong predictor of the primary composite endpoint. Time-dependent receiver operating characteristic analysis, net reclassification index, and integrated discrimination improvement showed that the addition of positive TaVR to conventional HCM risk factors improved prediction of arrhythmic events. However, in subgroup analysis, a positive TaVR lost statistical significance in patients with apical HCM but remained significant in patients with all other hypertrophy patterns. CONCLUSION: Positive TaVR is associated with MAE in HCM patients, independent of and incremental to traditional risk factors.