ABSTRACT
BACKGROUND: Vasovagal syncope (VVS) is a common clinical condition involving genetic background. The role of beta-blockers in the treatment is controversial. OBJECTIVE: The aim of this study was to investigate the effect of beta-1 gene polymorphism on beta-blocker therapy in patients with VVS. METHODS: We included 123 patients who were diagnosed with VVS after the tilttable test. We searched for the polymorphism Arg389Gly (rs1801253) in the beta-1 adrenoceptor gene. RESULTS: Overall, 64 patients (52%) had Arg389Arg with Arg389Arg genotype were more frequent compared with patients having Arg389Gly genotype (total syncopal episodes [TSE], 7.9 ± 3.7 vs. 6.4 ± 3.0; p = 0.012). TSE in patients with Arg389Arg genotype decreased significantly after 18 months of beta-blocker treatment (7.9 ± 3.7 vs. 3.0 ± 1.4, p < 0.001). After 18 months of beta-blocker treatment, patients with Arg389Arg genotype had significantly fewer syncopal episodes than patients with Arg389Gly genotype (3.0 ± 1.4 vs. 6.8 ± 3.2, p < 0.001). CONCLUSIONS: Results of beta-blocker therapy in patients with Arg389Arg genotype suggest that VVS pathophysiology is a multifactorial condition, with genetic, psychological, and environmental components, and therefore, treatment selection can be based on gene polymorphism.
ABSTRACT
Inadequate ablation lesion formation may be responsible for post-ablation ventricular tachycardia (VT) recurrences.We aimed to evaluate whether visualisation of radiofrequency (RF) lesion size by cardiac magnetic resonance imaging (CMR) has any role in predicting adequacy of lesion and in estimating outcome.Retrospective pilot studyNine consecutive patients (8 male, age 60â±â13 years) underwent ablation for sustained VT because of ischemic scar were evaluated for pre- and post-procedure scar tissue by CMR to characterize ablation lesions. Microvascular obstruction (MVO) surrounded by late gadolinium enhancement was defined as irreversible RF lesion. All patients were followed for at least 6 months for recurrences.Five of the patients had previous inferior myocardial infarction (MI), whereas remaining 4 had anterior MI. Acute procedural success, as defined by termination of the arrhythmia without recurrence in 30 minutes, was attained in all patients. Contrast enhancement and wall motion abnormality in presumed infarction area were confirmed by pre-ablation CMR images. MVO was detected at the reported ablation site in 6/9 patients, all arrhythmia- and symptom-free at median 24 months (range 8-38 months) follow-up. In remaining 3 patients who had VT recurrence (clinical VT in 2, sustain VT with a new morphology in 1), MVO was not detected despite achievement of acute procedural success. There was no correlation with pre-ablation scar size and clinical arrhythmia recurrence.CMR is a useful imaging modality to guide ablation procedures by detecting scar tissue. Additionally MVO seen by post-procedural imaging may be related to adequacy of RF ablation lesions and may correlate with clinical outcome.
Subject(s)
Catheter Ablation/adverse effects , Cicatrix/diagnostic imaging , Magnetic Resonance Angiography/statistics & numerical data , Myocardial Ischemia/diagnostic imaging , Postoperative Complications/diagnostic imaging , Tachycardia, Ventricular/diagnostic imaging , Aged , Arrhythmias, Cardiac/diagnostic imaging , Arrhythmias, Cardiac/etiology , Catheter Ablation/methods , Cicatrix/etiology , Contrast Media , Female , Gadolinium , Humans , Male , Microvessels/diagnostic imaging , Middle Aged , Myocardial Ischemia/etiology , Pilot Projects , Postoperative Complications/etiology , Prognosis , Recurrence , Retrospective Studies , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/surgeryABSTRACT
BACKGROUND: The two predominant etiologies of right ventricular tachycardia (VT) are arrhythmogenic right ventricular cardiomyopathy (ARVC) and idiopathic VT arising from the right ventricular outflow tract (RVOT). Discrimination between these two entities is critical, as their prognoses and therapeutic options differ. The Tpeak -Tend (Tpe) interval reflects the transmural repolarization dispersion and its prolongation is associated with high mortality. METHODS: We compared the sinus rhythm electrocardiogram (ECG) of 43 patients (24 male, 43 ± 16 years) with VT originating from right ventricle. Five patients under antiarrhythmic drug therapy were excluded. Tpe interval was measured in each precordial leads and compared among patients with ARVC and RVOT-VT. RESULTS: Twenty-five patients (16 male, 42 ± 16 years) met the Task Force criteria for the diagnosis of ARVC, and 13 patients (seven male, 45 ± 14 years) had idiopathic RVOT tachycardia. Patients with ARVC had significantly prolonged Tpe intervals in all precordial leads compared to patients with idiopathic RVOT VT (137.1 ± 32.6 ms vs 93.8 ± 16.9 ms; P < 0.001 in V1, 133.2 ± 35.5 ms vs 104.7 ± 16.9 ms; P = 0.01 in V2, 125.7 ± 31.5 ms vs 99.1 ± 19.6 ms; P = 0.09 in V3, 121.9 ± 26.5 ms vs 92.3 ± 19.7 ms; P = 0.001 in V4, 123.1 ± 26.5 ms vs 99.5 ± 20:1 ms; P = 0.04 in V5 and 126.9 ± 32.2 ms vs 89 ± 11.3 ms; P < 0.001 in V6, respectively). For the diagnosis of ARVC, Tpe cut-off value of 97 ms in V1 had 84% sensitivity and 62% specificity (area under curve = 0.880). CONCLUSION: In patients with VT of RV origin, the prolonged Tpe interval in sinus rhythm electrocardiogram supports the diagnosis of ARVC.
