ABSTRACT
Background: Myocardial infarction is one of the major causes of sudden death in present era and cardiac arrhythmias are common complications of it. Material and methods: Present study was conducted at intensive coronary care unit (I.C.C.U) of tertiary care hospital, Ahmedabad on 100 cases of acute myocardial infarction to study the incidence of arrhythmia and their nature in relation with the site of infarction and to evaluate prognostic value of arrhythmias in Acute Myocardial Infraction (AMI). Results: Incidence of various arrhythmias was 76% in present study. S. tachycardia was more common (68%) than S. bradycardia (19%). S. tachycardia and tachyarrhythmia occurred more commonly with anterior wall myocardial infarction, while S. bradycardia and bradyarrhythmia with inferior wall myocardial infarction. Conclusion: Study of incidence of various cardiac arrhythmias, their nature and relation to site of infarction as well as prognostic value in patients of acute myocardial infarction proper treatment.
ABSTRACT
OBJECTIVE: To evaluate, on a retrospective basis, the anatomic characteristics of the arterial supply to the sinoatrial node (SAN) in the Korean population using an ECG-gated multi-detector CT (MDCT). MATERIALS AND METHODS: The electrocardiographic-gated MDCTs of 500 patients (258 men and 242 women; age range, 17-83 years; mean age, 58.6 +/- 12.04 years) were analyzed retrospectively. In each case, the SAN artery (arteries) was named according to a special nomenclature with regard to origin, course, and termination. RESULTS: A total of 516 SAN arteries were visualized in 496 patients. The SAN was supplied by a single artery in 476 (96.4%) cases and by 2 arteries in 18 (3.6%) cases. The SAN originated from the right coronary artery in 265 (53.4%) cases and from the left circumflex in 213 (43%) cases. CONCLUSION: This study can provide basic data on variations of the SAN artery in the Korean population.
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cardiac-Gated Imaging Techniques , Coronary Vessel Anomalies/diagnostic imaging , Republic of Korea , Retrospective Studies , Sinoatrial Node/diagnostic imaging , Tomography, X-Ray Computed/methodsABSTRACT
Recent electrophysiological data have provided the evidences that background currents such as Na(+)-Ca2+ exchange can significantly modulate cardiac pacemaker activity. In this study, the effects of extracellular Na+ and Ca2+ concentrations on the pacemaker activity were investigated by measuring the intracellular Na+ activity (aiNa) with Na(+)-selective microelectrodes and the results are summarized as follows. 1) In the rabbit SA node, aiNa was 3.2 +/- 0.3 mM and mean MDP (maximal diastolic potential) was -63.3 +/- 1.4 mV. 2) Graded decreases of external Na+ concentration resulted in the loss of spontaneous beating, hyperpolarization and the decrease of aiNa. 3) An increase in extracellular Ca2+ concentration in low Na+ solution augmented the transient decrease of aiNa, about 3 minutes in low Na+ solution, until aiNa started to increase. 4) In low Na+ solution, which had extracellular Ca2+ concentration according to the calculation based on the equilibrium state of Na+-Ca2+ exchange, aiNa was continuously decreased. It was concluded that intracellular Na+ activity modulated by Na+-Ca2+ exchange could play an important role in the initiation of pacemaker potential.