To identify genetic factors influencing cardiac conduction, we carried out a genome-wide association study of electrocardiographic time intervals in 6,543 Indian Asians. We identified association of a nonsynonymous SNP, rs6795970, in SCN10A (P = 2.8 x 10(-15)) with PR interval, a marker of cardiac atrioventricular conduction. Replication testing among 6,243 Indian Asians and 5,370 Europeans confirmed that rs6795970 (G>A) is associated with prolonged cardiac conduction (longer P-wave duration, PR interval and QRS duration, P = 10(-5) to 10(-20)). SCN10A encodes Na(V)1.8, a sodium channel. We show that SCN10A is expressed in mouse and human heart tissue and that PR interval is shorter in Scn10a(-/-) mice than in wild-type mice. We also find that rs6795970 is associated with a higher risk of heart block (P < 0.05) and a lower risk of ventricular fibrillation (P = 0.01). Our findings provide new insight into the pathogenesis of cardiac conduction, heart block and ventricular fibrillation.

The objective of the study was to determine the reliability of ECG precordial electrode placement by doctors and nurses involved in the emergency care of patients admitted with suspected cardiac diseases. A total of 120 subjects were recruited within 2 days from six hospitals. They comprised physicians, nurses and cardiac technicians involved in the clinical assessment and care of patients with suspected cardiac disease. Subjects were asked to complete a questionnaire and marked on two diagrams of the chest wall the positions they would place precordial electrodes V1-V6. This study showed wide inter-individual and inter-group variations in the placement of electrodes. Notably, V1 and V2 were frequently incorrectly positioned in the second intercostal space, especially by physicians. The correct position of V1 in the fourth right intercostal space was identified by 90% of cardiac technicians, 49% of nurses, 31% of physicians (excluding cardiologists) and--most disappointing of all--only 16% of cardiologists (p<0.001 for inter-group differences). V5 and V6 were also often mispositioned, too high on the lateral chest wall. Nurses and doctors (especially cardiologists) do not know the correct positions for ECG electrodes. Because incorrect positioning of the precordial electrodes changes the ECG significantly, patients are at risk of potentially harmful therapeutic procedures. Equally, doctors who are aware of the possibility of lead misplacement may be inclined to ignore some ECG changes that may be genuine evidence of ischaemia. The only safe solution is proper precordial electrode placement, which requires training and an environment supporting precision.

Evidence is based on a single large trial analysis as the other trial was small, with inadequate power to detect survival difference. Chemotherapy-naive patients with HGG at first recurrence when treated with PCV or TMZ have similar survival and time-to-progression outcomes. Adverse events are similar and QoL scores are statistically but not clinically significant between TMZ and PCV. Further RCTs should be conducted with adequate power following CONSORT guidelines with emphasis on QoL outcomes.

Isolated anomalous origin of right coronary artery is a rare developmental anomaly which is mostly asymptomatic and is discovered incidentally. We present a case of a 21-year-old male who presented with chest pain and was found to have anomalous origin of right coronary artery from pulmonary artery for which he underwent prompt surgical correction.