Familial pseudo-Wolff-Parkinson-White syndrome.

INTRODUCTION: PRKAG2 plays a role in regulating metabolic pathways, and mutations in this gene are associated with familial ventricular preexcitation, hypertrophic cardiomyopathy, and atrioventricular conduction disturbances. Clinico-pathologic and experimental data suggest the hypothesis of a glycogen storage disease. OBJECTIVE: To report a unique pattern of clinical features observed in individuals with a mutant PRKAG2 from two unrelated families. METHODS AND RESULTS: We studied two large families and found a total of 20 affected individuals showing a combination of sinus bradycardia, short PR interval, RBBB, intra and infrahisian conduction disturbances often requiring a pacemaker, and atrial tachyarrhythmias. Three individuals died suddenly at a young age. No patient had the Wolff-Parkinson-White (WPW) syndrome, and only two patients (10%) had myocardial hypertrophy. We performed screening of the exons and exon-intron boundaries of PRKAG2. Genetic analysis revealed a missense mutation (Arg302Gln) in the affected individuals from both families. This mutation had been described before and has been associated with the familial form of the WPW syndrome and with a high prevalence of left ventricular hypertrophy. CONCLUSION: PRKAG2 mutations are responsible for a diverse phenotype and not only the familial form of the WPW syndrome. Familial occurrence of right bundle branch block, sinus bradycardia, and short PR interval should raise suspicion of a mutant PRKAG2 gene.

Decrease of plasma triglycerides during the acute phase of unstable angina or non-ST elevation myocardial infarction is a marker of recurrent ischemia.

Both increase and decrease of plasma triglycerides during acute coronary syndromes (ACS) are reported, however, a clinical relevance for these distinct metabolic responses is unclear. To test the association between distinct responses of lipid metabolism and cardiovascular risk, 39 subjects admitted with non-ST elevation ACS within 48 h of presentation had plasma lipids measured on the first and sixth days of hospitalization, and continuous electrocardiogram was performed during the first 2 days to quantify recurrent ischemia and heart rate variability. No lipid-lowering therapy was offered to the patients. During the first 5 days, half of them experimented a decrease in triglycerides (n=19, median: -18 mg/dl) and the other half presented triglyceride increase (n=20, median: +44 mg/dl). A higher incidence of recurrent ischemia (35% versus 5%, P=0.02) and greater ischemic burden/patient (123 +/- 286 mm min versus 47 +/- 212 mm min, P=0.02) were observed in subjects with triglyceride reduction, when compared with those with triglyceride increase. Individuals with heart rate variability below the median presented a median decrease in triglycerides during the 5-day period, as opposed to the counterparts (P=0.05). In conclusion, triglyceride reduction during ACS is associated with a greater incidence of recurrent ischemia and may constitute a sign of higher sympathetic activity.

Anti-inflammatory effect of atorvastatin (80 mg) in unstable angina pectoris and non-Q-wave acute myocardial infarction.

In this randomized trial, C-reactive protein increased during the first 5 days of an acute coronary syndrome in patients treated with placebo, but this phenomenon was not observed in those randomized to atorvastatin 80 mg/day. This suggests that short-term statin therapy inhibits inflammation in patients with non-ST-elevation acute coronary syndromes.