Heart rhythm : the official journal of the Heart Rhythm Society
-
Patients with hypertrophic cardiomyopathy (HCM) and aborted cardiac arrest are generally regarded as a high-risk subgroup susceptible to future major cardiac events and an unfavorable prognosis. However, outcome over extended time periods after major arrhythmic events is unresolved in such HCM patients. ⋯ In HCM, long-term survival up to 30 years may follow cardiac arrest with or without ICD intervention. Disabling heart failure symptoms were uncommon after these arrhythmic events, at last follow-up. These novel observations regarding the natural history of HCM underscore the unpredictability of the arrhythmogenic substrate, which may remain dormant over extended periods of time.
-
Long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) are two of the most common, potentially lethal, cardiac channelopathies. Treatment strategies for the primary and secondary prevention of life-threatening polymorphic ventricular tachycardia/fibrillation include pharmacotherapy with beta-blockers, implantable cardioverter defibrillators, and left cardiac sympathetic denervation (LCSD). ⋯ We present a series of 20 patients with LQTS and CPVT who underwent LCSD, 18 using VATS. The minimally invasive VATS surgical approach was associated with minimal perioperative complications, including no intraoperative ectopy and excellent immediate and short-term outcomes. Videoscopic denervation surgery, in addition to traditional LCSD, offers a safe and effective treatment option for the personalized medicine required for patients with LQTS/CPVT.
-
Comparative Study
Prevalence of long and short QT in a young population of 41,767 predominantly male Swiss conscripts.
Abnormally long and short QT intervals are recognized to be associated with an increased risk for life-threatening ventricular arrhythmias. It is therefore important to define the upper and lower border of the normal QT. ⋯ The present study shows the distribution of QT intervals in an unselected young population. Because none of the subjects presented a QTc < 300 ms, it may be concluded that the short QT syndrome is a very rare entity in the population of young male adults.
-
Heart rate variability (HRV), calculated in the frequency or time domain, decreases in congestive heart failure (CHF). In HRV power spectral analysis, the low-frequency (LF) component diminishes in patients with CHF and the decrease is related to an increased risk of sudden death. ⋯ The spectral variables (LF power and the LF/HF ratio) and direct variables measuring sympathetic nerve activity (iSGNA) correlate at baseline but not during CHF. At baseline, the vagal activity (iVNA) is associated with an increase in HFnu and a decrease in LFnu. These data indicate that the reduction in LF power and LF/HF ratio observed in heart failure dogs are likely to reflect a diminished sinus node responsiveness to autonomic modulation or an abnormal baroreflex function rather than an increased sympathetic activity.