International journal of cardiology
-
Editorial Comment
Mutation-specific effects of lidocaine in Brugada syndrome.
Brugada syndrome (BrS) is a hereditary cardiac disease characterized by right bundle-branch block, an elevation of the ST-segment in leads V1 through V3 on the electrocardiogram, and ventricular fibrillation that can lead to sudden cardiac death. Mutations in the cardiac sodium channel gene SCN5A, which encodes the alpha-subunit of the human cardiac voltage-dependent Na+ channel (Na(v)1.5), are identified in 15-30% of patients with BrS. Most SCN5A mutations lead to a 'loss-of-function' phenotype, reducing the Na+ current during the early phases of the action potential. ⋯ However, the N406S mutation in SCN5A causes distinct gating defects and enhanced intermediate inactivation of Na+ channels, which led to unexpected pharmacological effects of lidocaine in a patient carrying this mutation. In the presence of the N406S mutation, use-dependent block by lidocaine is reduced and recovery from intermediate inactivation is hastened by lidocaine. These findings suggest that lidocaine may improve the Brugada phenotype in patients with N406S by increasing the availability of Na+ channels.
-
Comparative Study
Plasma brain natriuretic peptide levels, right ventricular volume overload and exercise capacity in adolescents after surgical repair of tetralogy of Fallot.
Right ventricular (RV) volume overload secondary to pulmonary regurgitation contributes to long-term morbidities in patients after tetralogy of Fallot (TOF) repair. We tested the hypothesis that plasma brain natriuretic peptide (BNP) levels relate to RV volume overload, pulmonary regurgitation, and exercise capacity in adolescents after TOF repair. ⋯ In adolescent patients after TOF repair, plasma BNP levels relate to RV volume overload, pulmonary regurgitation and exercise capacity.
-
Preliminary data have shown that colchicine may be considered for the prevention of the postpericardiotomy syndrome (PPS). The COlchicine for the Prevention of Post-pericardiotomy Syndrome (COPPS) study is a multicenter, double blind, placebo-controlled, randomized trial that will enroll 360 patients after cardiac surgery. The primary end point will be the PSS rate at 12 months. The study will be the first large randomized placebo-controlled trial in this area, and will provide important evidence regarding the possible benefit of colchicine for the primary prevention of the PPS.
-
Letter Case Reports
Hymenoptera sting-induced Kounis syndrome: effects of aspirin and beta-blocker administration.
Kounis syndrome is the concurrence of acute coronary syndromes with conditions associated with activation of interacting inflammatory cells including allergic or hypersensitivity and anaphylactic or anaphylactoid insults. It is caused via inflammatory mediators released during inflammatory cell activation. A variety of conditions, drugs, and environmental exposures can induce Kounis syndrome. ⋯ This was followed by retrosternal pain, chest discomfort and electrocardiographic changes compatible with acute myocardial ischemia. Cardiac enzymes, troponins and blood pressure remained normal but serum tryptase was raised. The clinical implications and pathophysiology of this rare association are discussed.
-
Letter Case Reports
Thiamine deficiency as a rare cause of reversible severe pulmonary hypertension.
In developed countries, the incidence of cardiac beriberi is rare. It can lead to high output cardiac failure and pulmonary hypertension. We hereby report an atypical case of beriberi heart with reversible right heart failure and severe pulmonary hypertension. Thiamine deficiency can cause reversible pulmonary hypertension, and it must be included in the differential diagnosis in patients with high risk of nutritional deficiency.