Age and Gender Distribution of Patients with Acute Myocardial Infarction Admitted to University Hospitals during the Period of 1990-1999

BACKGROUND AND OBJECTIVES: The prevalence of coronary disease in Korea, with the consequent morbidity and mortality, has rapidly risen during the last two decades. This study aimed to describe the changing pattern in the demographic composition during the 1990s of patients presenting with acute myocardial infarction (AMI) in Korean metropolitan cities. SUBJECTS AND METHODS: Data from the medical record of patients with AMI, admitted to five University Hospitals in Busan and Daegu between January 1990 and December 1999, were sorted according to their age (75 years) and gender. RESULTS: During the last decade, the number of cases of AMI increased from 283 in 1990, to 988 by 1999 (ratio of AMI/medical patients admitted; 1.68% in 1990 to 2.52% in 1999). The most prevalent age group was 6074 yrs (46.1%), followed by 4559 yrs (34.2%). Generally, the male cases were twice as prevalent as female (68.2% : 31.8%), but the gender ratio was reversed in the highest age group (>75 yrs) (44.6% : 55.4%). During the period in question, the gender ratio and age distribution remained reasonably constant throughout. The proportion of younger AMI patients (<45 yrs) did not increase. CONCLUSION: Admissions due to AMI increased substantially during the 1990s. Almost half the cases were from the 6074 yrs age group, and two third were male. There were little changes in the compositions of age and gender of the AMI cases during this period.

Diagnosis of sick sinus syndrome with intravenous adenosine injection

BACKGROUND: The most widely utilized indexes of sinus node dysfunction are the sinus node recovery time (SNRT) and the corrected sinus node recovery time (CSNRT), which generally require catheterization. Adenosine has negative chronotropic effect on the sinoatrial node. Non-invasive and reliable sinus node function test with intravenous adenosine was investigated. METHODS AND RESULT: The clinical value of rapid intravenous injection of adenosine for assessing sinus node dysfunction was examined in 14 patients with sick sinus syndrome (SSS) and 31 controls. After prophylactic insertion of a temporary pacemaker in the right ventricle, overdrive suppression test was conducted using the standard technique and CSNRT was measured to evaluate the sinus node function. Then, the CSNRT after administration of an intravenous bolus of adenosine (6 mg and 12 mg) was measured. Post-adenosine corrected sinus node recovery time (ADO: SNRT) was calculated by subtracting the basal sinus cycle length from the longest sinus cycle length. When ADO: SNRT over 550 msec was assumed as an indicator of sinus node dysfunction, intravenous injection of 6 mg of adenosine had a sensitivity of 85% and specificity of 100%, and 12 mg of adenosine had a sensitivity of 100% and specificity of 90% for detection of sick sinus syndrome. There were significant differences in ADO: SNRT between patient and control group (6 mg 1501+/-1081 msec vs 64+/-109 msec; 12 mg 4005+/-2055 msec vs 216+/-315 msec, respectively). CONCLUSION: he ADO: SNRT was a highly sensitive and specific index for diagnosing sick sinus syndrome, and should be considered as an alternative to invasive testing in patients with suspected sick sinus syndrome.

Initiation of Torsades de pointes by head-up tilt test in congenital long QT syndrome patient

Long QT syndrome is a cardiac disorder of repolarization which is characterized by elctrocardiographic abnormalities including prolonged QT interval, T-wave abnormalities and polymorphic ventricular tachycardia known as Torsades de Pointes. Its clinical manifestation are recurrent syncope, seizure, and sudden death. Recently,we experienced Torsades de Pointes(TdP) by head-up tilt test in 24 year-old female patient presenting recurrent syncope and long QT interval. Beta-blocker and left cervicothoracic sympathetic ganglionectomy were not effictive, then we tried mexiletine. After mexiletine medication, the QT interval was significantly shortened and there was no more syncope.

Implantation of ICD in a Ventricular Fibrillation Patient with a High Defibrillation Threshold

ICD (implantable cardioverter-defibrillator) has been recently accepted as the most effective treatment for patients with medically refractory or life threatening ventricular tachycardia or ventricular fibrillation. Determination of the DFT (defibrillation threshold) is important in the implantation of ICD. DFT is the lowest shock energy that successfully terminates ventricular fibrillation. Preoperative amiodarone use, increased body size, and left ventricular dilatation are associated with high DFT. Recently, we experienced a 66 year-old male patient presenting with syncope due to idiopathic ventricular fibrillation in whom DFT was high and unstable, probably due to preoperative use of amiodarone.