Background-Routine diagnostic work-up occasionally does not identify any abnormality among patients with monomorphic ventricular arrhythmias (VAs) of left ventricular (LV) origin. Aim of this study was to investigate the value of cardiac MRI (cMRI) for the diagnostic work-up and prognostication of these patients. Methods and Results-Forty-six consecutive patients (65% males; mean age, 44±15 years) with monomorphic VAs of LV origin and negative routine diagnostic work-up were included. Seventy-four consecutive patients (60% males; mean age, 40±17 years) with apparently idiopathic monomorphic VAs of right ventricular origin served as control group. Both groups underwent comprehensive cMRI study and were followed-up for a median of 14 months (25th-75th percentiles, 7-37 months). The outcome event was an arrhythmic composite end point of sudden cardiac death or nonfatal episode of ventricular fibrillation or sustained ventricular tachycardia requiring external cardioversion or appropriate implantable cardioverter defibrillator therapy. The 2 groups of patients did not differ in age (P=0.14) and sex (P=0.57). No significant difference was observed between patients with VAs of LV origin and VAs of right ventricular origin about biventricular volumes and systolic function. cMRI demonstrated myocardial structural abnormalities in 19 (41%) patients with VAs of LV origin versus 4 (5%) patients with VAs of right ventricular origin (P<0.001). The outcome event occurred in 9 patients; myocardial structural abnormalities on cMRI were significantly related to the outcome event (hazard ratio, 41.6; 95% confidence interval, 5.2-225.0; P<0.001). identification of concealed cardiac abnormalities in patients with apparently idiopathic LV arrhythmias. Moreover, scarce data are available about the prognostic value of concealed structural abnormalities detected by cMRI in these patients. Accordingly, the aim of this study was 2-fold: (1) to investigate the value of comprehensive cardiac magnetic resonance tissue characterization imaging, including T1-weighted imaging, T2-weighted imaging, and late gadolinium enhancement (LGE) imaging, for the detection of structural changes in patients with monomorphic VAs of LV versus RV origin and negative routine diagnostic work-up; and (2) to determine the prognostic value of concealed structural abnormalities detected by cMRI in these patients.
Conclusions-Myocardial
Methods
Patient PopulationA total of 46 consecutive patients with monomorphic VAs of LV origin (ie, frequent premature ventricular beats [PVBs] >1000/24 hours, nonsustained ventricular tachycardia [NSVT], or sustained ventricular tachycardia [SVT] with right bundle branch block [RBBB] morphology) and negative routine diagnostic work-up were included in the study. Negative routine diagnostic work-up was defined on the basis of (1) absence of systemic diseases, arterial hypertension, and diabetes mellitus; (2) absence of plasma electrolyte abnormalities; (3) normal 12-lead ECG; (4) normal 2-dimensional echocardiography; and (5) absenc...
Pharmacologic challenge with sodium channel blockers is part of the diagnostic workout in patients with suspected Brugada syndrome. The test is overall considered safe but both ajmaline and flecainide detain well known pro-arrhythmic properties. Moreover, the treatment of patients with life-threatening arrhythmias during these diagnostic procedures is not well defined. Current consensus guidelines suggest to adopt cautious protocols interrupting the sodium channel blockers as soon as any ECG alteration appears. Nevertheless, the risk of life-threatening arrhythmias persists, even adopting a safe and cautious protocol and in absence of major arrhythmic risk factors. The authors revise the main published case studies of sodium channel blockers challenge in adults and in children, and summarize three cases of untreatable ventricular arrhythmias discussing their management. In particular, the role of advanced cardiopulmonary resuscitation with extra-corporeal membrane oxygenation is stressed as it can reveal to be the only reliable lifesaving facility in prolonged cardiac arrest.
Left ventricular (LV) twist (LVT) and untwisting (LVUT) rate are global and thorough parameters of LV function. The aim of the present study was to investigate the differences in LV rotational mechanics between patients with cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM). Twenty consecutive patients with CA, 20 consecutive patients with HCM, and 20 consecutive subjects without evidence of structural heart disease were included. Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging was performed to evaluate biventricular function, LV mass index, and presence/extent of LGE. Feature-tracking analysis was applied to LV basal and apical short-axis images to determine peak LVT, time to peak LVT, peak LVUT rate, and time to peak LVUT rate. Peak LVT and peak LVUT rate were significantly impaired in patients with CA compared with controls (P < 0.05 for both). In patients with HCM, peak LVT was increased (P < 0.05) compared with controls, whereas peak LVUT rate was preserved (P > 0.05). Time to peak LVUT rate was significantly prolonged in patients with CA and in patients with HCM compared with controls (ANOVA P < 0.001). At multivariate analysis, age (P = 0.007), LV ejection fraction (P = 0.035) and extent of LGE (P < 0.001) were independently related to peak LVT, and LV mass index (P = 0.015) and extent of LGE (P = 0.004) were independently related to peak LVUT rate, whereas extent of LGE (P < 0.001) was the only variable independently related to time to peak LVUT rate. In conclusion, CA and HCM have specific behavior of LV rotational mechanics. The extent of LGE significantly influences the LV rotational mechanics.
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