Structural and Functional Impact of Adrenoceptor Beta-1 Gene Polymorphism in Patients with Hypertrophic Cardiomyopathy and Response to Beta-Blocker Therapy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a genetically inherited cardiac disorder with diverse clinical presentations. Adrenergic activity, primarily mediated through beta-adrenoceptors, plays a central role in the clinical course of HCM. Adrenergic stimulation increases cardiac contractility and heart rate through beta-1 adrenoceptor activation. Beta-blocker drugs are recommended as the primary treatment for symptomatic HCM patients to mitigate these effects. METHODS: This prospective study aimed to investigate the impact of common ADRB-1 gene polymorphisms, specifically serine-glycine at position 49 and arginine-glycine at position 389, on the clinical and structural aspects of HCM. Additionally, the study explored the association between these genetic variations and the response to beta-blocker therapy in HCM patients. RESULTS: A cohort of 147 HCM patients was enrolled, and comprehensive assessments were performed. The findings revealed that the Ser49Gly polymorphism significantly influenced ventricular ectopic beats, with beta-blocker therapy effectively reducing them in Ser49 homozygous patients. Moreover, natriuretic peptide levels decreased, particularly in Ser49 homozygotes, indicating improved cardiac function. Left ventricular outflow obstruction, a hallmark of HCM, was also reduced following beta-blocker treatment in all patient groups. In contrast, the Arg389Gly polymorphism did not significantly impact baseline parameters or beta-blocker response. CONCLUSION: These results emphasize the role of the Ser49Gly polymorphism in the ADRB-1 gene in shaping the clinical course and response to beta-blocker therapy in HCM patients. This insight may enable a more personalized approach to managing HCM by considering genetic factors in treatment decisions. Further research with larger populations and longer follow-up periods is needed to confirm and expand upon these findings.

Diagnostic accuracy of Apple Watch Series 6 recorded single-lead ECGs for identifying supraventricular tachyarrhythmias: a comparative analysis with invasive electrophysiological study.

BACKGROUND: The advancements in wearable technology have made the detection of arrhythmias more accessible. While smartwatches are commonly used to detect patients with atrial fibrillation, their effectiveness in the differential diagnosis of supraventricular tachycardias (SVT) lacks consensus. METHODS: A study was conducted on 47 patients with documented SVTs on a 12-lead ECG. All patients in the cohort underwent electrophysiology study with induction of SVT. A 6th generation Apple Watch was used to record ECG tracings during baseline sinus rhythm and during induced SVT. Cardiology residents and attending cardiologists evaluated these recordings to diagnose the differential diagnosis of SVT. RESULTS: The evaluation revealed 27 cases of typical atrioventricular nodal reentrant tachycardia (AVNRT), 11 cases of atrioventricular reentrant tachycardia (AVRT), and 9 cases of atrial tachycardia/atrial flutter (AT/AFL) among the induced tachycardias. Attending physicians achieved an accuracy of 66.0 to 76.6%, and residents demonstrated accuracy rates between 68.1 and 74.5%. Interrater reliability was assessed using Fleiss's Kappa method, resulting in a moderate level of agreement between residents (Kappa = 0.465, p < 0.001, 95% CI 0.30-0.63) and attendings (Kappa = 0.519, p < 0.001, 95% CI 0.35-0.68). The overall Kappa value was 0.417 (p < 0.001, 95% CI 0.34-0.49). CONCLUSIONS: Smartwatch recordings demonstrate moderate feasibility in diagnosing SVT when following a pre-specified algorithm. However, this diagnostic performance was lower than the accuracy obtained from 12-lead ECG tracings when blinded to procedure outcomes.

Pulmonary Hypertension Due to High-Output Heart Failure: Hereditary Hemorrhagic Telangiectasia.

Pulmonary hypertension (PH) is a complex disorder that should be managed with a multidisciplinary approach. Although most of the underlying causes of left heart disease can be easily diagnosed with cardiac imaging, some pathologies might necessitate careful investigation to go beyond the obvious. High-output heart failure (HF) due to arteriovenous malformation (AVMs) is an unnoticeable cause for HF and PH. Patients with hepatic AVMs should always be carefully evaluated with regard to hereditary hemorrhagic telangiectasia (HHT) since they can have multiple signs related to the other systems without any symptoms. In this case report, we discussed a patient who was initially diagnosed as PH associated with HF with preserved ejection fraction but eventually was found to have PH associated with high-output HF due to hereditary hemorrhagic telangiectasia (HHT, or Osler Weber Rendu syndrome) after detailed evaluation.

Left atrial functions in the early period after cryoballoon ablation for paroxysmal atrial fibrillation.

PURPOSE: In patients with paroxysmal atrial fibrillation (PAF), functional changes are observed in the left atrium (LA) after pulmonary vein isolation (PVI) procedure. Although previous studies have investigated the altered mechanical functions of the LA with radiofrequency (RF) ablation, changes in the LA functions in the early period after cryoablation (CB-2) have not been clearly demonstrated. This study aims to explore the early periodical changes in mechanical functions of the LA in patients with PAF who underwent CB-2 based ablation through the help of echocardiographic methods which contain Doppler and strain parameters. METHODS: Consecutive 77 patients (mean age: 57.5 ±  11.2; 57% men) with PAF underwent CB-2 were prospectively analyzed. All patients were in sinus rhythm before and after the procedure. The LA dimensions, the LA reservoir strain, the LA atrial contractile strain and the LA conduit strain and left ventricular diastolic function parameters were evaluated by Doppler echocardiography before and 3 months after the procedure. RESULTS: Acute procedural success was achieved in all cases. No major complications were observed. LA reservoir strain and LA contractile strain showed significant recovery after the procedure. (28.3 ± 12.8 vs. 34.6 ± 13.8, p < .001 and -10.8 ± 7.9 vs. -13.9 ± 9.3, p = .014 respectively). No significant change was demonstrated in other echocardiographic parameters. CONCLUSION: Significant improvement in mechanical functions may occur even in the early period after cryoballoon ablation in patients with PAF.

Intracardiac electrogram characteristics of intramural outflow tract ventricular arrhythmias.

BACKGROUND: Annotation of earliest depolarization which depends on maximum dV/dt of unipolar-electrograms and unipolar QS morphology identify site of origin for ventricular premature contractions (VPC). However, identification of unipolar QS morphology has limitations due to low spatial resolution. This study aims to compare electrogram characteristics at successful ablation site in patients with outflow tract (OT) VPC. METHODS: Local activation time (LAT), duration, and voltage data of each bipolar- and unipolar-electrogram at the successful ablation sites from the right ventricle OT (RVOT) and the left ventricle OT (LVOT) cases were analyzed. RESULTS: Forty-four of 60 (73%) of patients were ablated from RVOT and in 16/60 (27%) required ablation from both sides. All patients had acute VPC suppression. Bipolar-electrogram-QRS onset was earlier (36.4 ± 14.5 ms vs 26.3 ± 7.4 ms, p = 0.01), duration of bipolar-electrogram was shorter (56.9 ± 18.9 ms vs 78.9 ± 21.8 ms, p = 0.002), and bi-voltage amplitude was higher (3.2 ± 2.3 mV vs 1.4 ± 1.1 mV, p = 0.07) for patients with RVOT-only ablation. Mean bipolar-unipolar-electrogram difference was 4.4 ± 4.5 ms in the RVOT group vs 12.8 ± 4.9 ms in RVOT + LVOT group (p < 0.001). Unipolar QS morphology was recorded in 3.0 ± 3.9 vs 3.6 ± 1.8 cm2 in RVOT and RVOT + LVOT group, respectively (p = 0.41). Unipolar-electrogram revealed W pattern in 3/44 of RVOT vs 5/16 of RVOT + LVOT group, respectively (p = 0.01). In 18/60 (30%) of patients, unipolar QS was not identified at successful ablation site. CONCLUSION: QS in unipolar-electrogram was not a perfect predictor for successful ablation sites. Analysis of bipolar voltage amplitude and duration with bipolar-unipolar-electrogram time difference may identify presence of a deeper source.

An unexpected route of temporary pacing lead.

Congenital anomalies of the venous system including superior (SVC) and inferior vena cava are not uncommon. Failure of certain vessels embryogenesis results in numerous caval variations and anomalies. Anomalies of systemic venous circulation are frequently seen in patients with congenital heart disease and are sometimes incidentally recognized. However, these are usually without significant clinical implications, detection of these anomalies is necessary to avoid diagnostic pitfalls and for planning vascular interventions. We present a rare caval anomaly, a left-sided IVC with hemiazygos continuation to left SVC and coronary sinus.

Decreasing time between first diagnosis of paroxysmal atrial fibrillation and cryoballoon ablation positively affects long-term consequences.

BACKGROUND: Patients with atrial fibrillation (AF) usually experience a worsening of their AF burden over time. We aimed to investigate timing of pulmonary vein isolation (PVI) by cryoballoon (CB-2) after the first clinical diagnosis of AF on ablation-related outcomes. METHODS: A total of 132 consecutive patients with paroxysmal AF undergoing PVI by CB-2 were included in the study. The patients were retrospectively sorted into two groups to evaluate differences in AF recurrence risk associated with early ablation (n = 89), defined as within 365 days of first AF diagnosis, and late ablation (n = 365), defined as > 365 days after first AF diagnosis. AF-free survival during follow-up was compared between groups. RESULTS: Although mean procedure times were comparable between groups, mean fluoroscopy times were lower in the early ablation group. For the whole study group, median (interquartile range) time from AF diagnosis to first ablation was 4.0 (2.0-11.3) months [3.0 (1.0-4.0) vs 14.0 (12.0-22.5) months in the early and late ablation groups, respectively]. Median follow-up for the whole population was 12.0 (12.0-18.0) months, and after the blanking period, 14 (10.6%) patients had arrhythmia recurrence (2 in the early and 12 in the late ablation groups). In the univariable Cox regression analysis and propensity score adjusted penalized Cox regression analysis, there was a significant association between delay in ablation time and AF recurrence (unadjusted hazard ratio = 7.74, 95% CI 2.26-40.1, p < 0.001, adjusted hazard ratio = 7.50, 95% CI 2.23-38.6, p < 0.001). CONCLUSION: Delays in treatment with CB-2 ablation may negatively affect AF-free survival rates among patients with paroxysmal AF.

Catheter Ablation for Atrial Fibrillation in Patients ≤30 Years of Age.

Pulmonary vein (PV) automaticity is an established trigger for paroxysmal atrial fibrillation (PAF), making PV isolation (PVI) the cornerstone of catheter ablation. However, data on triggers for atrial fibrillation (AF) and catheter ablation strategy in very young patients aged <30 years are sparse. A total of 51 young patients (mean age 24.0 ± 4.2 years, 78.4% men) with drug-refractory PAF underwent electrophysiology (EP) study and ablation at 5 EP centers. None of the patients had structural heart disease or family history of AF. EP study induced supraventricular tachycardia (SVT) in 12 patients (n = 12, 23.5%): concealed accessory pathway mediated orthodromic atrioventricular reentrant tachycardia in 3 patients, typical atrioventricular nodal reentrant tachycardia in 6 patients, left superior PV tachycardia in 1 patient, left atrial appendage tachycardia in 1 patient, and typical atrial flutter in 1 patient. In patients with induced SVTs, SVT ablation without PVI was performed as an index procedure, except for the patient with atrial flutter who received cavotricuspid isthmus ablation in addition to PVI. Remaining patients underwent radiofrequency (n = 15, 29.4%) or second-generation cryoballoon-based PVI (n = 24, 47%). There were no major complications related to ablation procedures. Follow-up was based on outpatient visits including 24-hour Holter-electrocardiogram at 3, 6, and 12 months after ablation, or additional Holter-electrocardiogram was ordered in case of symptoms suggesting recurrence. Recurrence was defined as any atrial tachyarrhythmia (ATA) episode >30 seconds after a 3-month blanking period. A total of 2 patients with atrioventricular nodal reentrant tachycardia, 1 with left atrial appendage tachycardia, experienced AF recurrence within the first 3 months and received PVI. After the 3-month blanking period, during a median follow-up of 17.0 ± 10.1 months, 44 of 51 patients (86.2%) were free of ATA recurrence. In the PVI group, 33 of 39 patients (84.6%) experienced no ATA recurrence. In conclusion, SVT substrate is identified in around a quarter of young adult patients with history of AF, and targeted ablation without PVI may be sufficient in the majority of these patients. PVI is needed in the majority and is safe and effective in this population.

Echocardiographic assessment of left ventricular filling pressure in patients with acute ST elevation myocardial infarction: an invasive validation study.

Backgrounds Assessment of left ventricular filling pressure (LVFP) is of clinical importance in patients with ST elevation myocardial infarction (STEMI). Although several echocardiographic parameters are recommended for the assessment of LVFP, validation of these parameters in patients with STEMI is missing. We aimed to investigate the clinical utility of these parameters in acute settings. Methods: We prospectively included consecutive patients with STEMI. LV end-diastolic pressure (LVEDP) was measured following primary PCI and echocardiographic examination was performed within 24 hours. Mean left atrial pressure (mLAP) was calculated both invasively using Yamamoto's formula and non-invasively using Naugeh's formula. Mean LAP was considered increased when exceeded 18 mmHg. Results: Patients were grouped according to LVEDP, group 1(41 patients) and group 2(114 patients).There was no significant difference between groups in terms of comorbidities. NT pro-BNP levels (p < 0.001) and peak level of Hs-TnT (p-value: 0.002) were significantly higher in group 2. Average E/e' ratio was significantly higher in group 2 (10.19 ± 3.15 vs. 12.04 ± 4.83, p: 0.046). Isovolumetric relaxation time was longer in group 2 (p < 0.001) and left atrial volume index (LAVI) was also significantly higher in group 2 (p < 0.001). Regression analyses revealed that septal, lateral and average E/e' ratio, tricuspid regurgitation velocity, LAVI and left ventricular volume are correlated with mLAP. Among group 2 patients only 14 Patients fulfilled the increased LVFP criteria suggested by current guidelines. Conclusions Echocardiographic parameters indicating increased LVFP require validation and may need to be modified in patients with STEMI. Moreover, current algorithms underestimate the actual number of patients with increased LVFP.

The impact of lesion complexity on no-reflow phenomenon and predictors of reversibility in patients treated with primary percutaneous intervention.

OBJECTIVES: Complex coronary lesions are more prone to complications; however, the relationship between complex coronary lesions and no-reflow phenomenon in patients undergoing primary percutaneous intervention (pPCI) is still not clarified. Previous studies reported the association of total coronary artery complexity with no-reflow; however, impact of culprit lesion complexity on no-reflow is not known. In this study, we aimed to investigate the impact of culprit lesion complexity on no-reflow phenomenon. Furthermore, we aimed to investigate the factors that are related to reversibility of no-reflow. METHODS: We prospectively included 424 patients treated with pPCI. Patients' baseline characteristics and clinical variables were recorded. Reversibility of no-reflow was decided according to final angiography or ST resolution during the first hour following pPCI. There were 90 patients with a diagnosis of no-reflow constituted group 1 and patients without no-reflow constituted group 2. Complexity of coronary artery disease was assessed with SYNTAX score and culprit lesion complexity was assessed with both American College of Cardiology/Society of Cardiovascular Angiography and Interventions lesion classification and SYNTAX score. RESULTS: Complexity of culprit lesion was significantly higher in group 1 patients (type C lesion 76.6 vs. 27.8%; P < 0.001 and SYNTAX score 8.7 ± 3.0 vs. 6.2 ± 2.6; P < 0.001, respectively, group 1 vs. 2). Multivariate analyses revealed that lesion complexity is independently associated with no-reflow. Among 90 patients of group 1, 43 patients were classified as reversible no-reflow. Logistic regression analysis revealed that only ischaemia duration is independently associated with reversibility of no-reflow. CONCLUSION: Our study demonstrated that culprit lesion complexity is independently associated with no-reflow phenomenon and short ischaemic duration is significantly associated with reversibility of no-reflow.