Prevalence of Asymptomatic Atrial Fibrillation in Malaysian Patients with Hypertension

Atrial fibrillation (AF) is usually asymptomatic and often associated with established cardiovascular risk factors such as hypertension. The prevalence atrial fibrillation in patients admitted to Malaysian hospitals has been determined, but asymptomatic atrial fibrillation (AAF) in hypertensive patients in the primary care setting is not established. This study reports the prevalence of AAF in hypertensive patients in Malaysia, in a primary care setting. The overall prevalence of AAF was 0.75% with no differences between the gender. The prevalence of AAF increases with age – in the age groups of 30-39, >40-49, >50-59, >60-69, 70-79 and >80 years old were 0%, 0.17%, 0.35%, 2.32%, 2.59%, and 0% respectively. Hypertensive patients with age of ≥ 61 year old were associated with a probability of 10.6 times higher for AAF. We suggest the age threshold to screen for AAF to be age of 60. It is estimated that there are 49,029 Malaysians with AAF in 2010. A large population is at risk of AAF-related complications. There is justification for an even greater emphasis on diagnostic, primary and secondary prevention strategies.

Assessment of global and regional left ventricular function using 64-slice multislice computed tomography and 2D echocardiography: a comparison with cardiac magnetic resonance.

OBJECTIVES: To compare the assessment of global and regional left ventricular (LV) function using 64-slice multislice computed tomography (MSCT), 2D echocardiography (2DE) and cardiac magnetic resonance (CMR). METHODS: Thirty-two consecutive patients (mean age, 56.5+/-9.7 years) referred for evaluation of coronary artery using 64-slice MSCT also underwent 2DE and CMR within 48h. The global left ventricular function which include left ventricular ejection fraction (LVEF), left ventricular end diastolic volume (LVdV) and left ventricular end systolic volume (LVsV) were determine using the three modalities. Regional wall motion (RWM) was assessed visually in all three modalities. The CMR served as the gold standard for the comparison between 64-slice MSCT with CMR and 2DE with CMR. Statistical analysis included Pearson correlation coefficient, Bland-Altman plots and kappa-statistics. RESULTS: The 64-slice MSCT agreed well with CMR for assessment of LVEF (r=0.92; p<0.0001), LVdV (r=0.98; p<0.0001) and LVsV (r=0.98; p<0.0001). In comparison with 64-slice MSCT, 2DE showed moderate correlation with CMR for the assessment of LVEF (r=0.84; p<0.0001), LVdV (r=0.83; p<0.0001) and LVsV (r=0.80; p<0.0001). However in RWM analysis, 2DE showed better accuracy than 64-slice MSCT (94.3% versus 82.4%) and closer agreement (kappa=0.89 versus 0.63) with CMR. CONCLUSION: 64-Slice MSCT correlates strongly with CMR in global LV function however in regional LV function 2DE showed better agreement with CMR than 64-slice MSCT.

Accuracy of 64-row multidetector computed tomography in detecting coronary artery disease in 134 symptomatic patients: influence of calcification.

BACKGROUND: The new 64-row multidetector computed tomography (CT)-assisted angiography can now detect coronary artery disease with shorter breath-hold time and at faster heart rates for symptomatic patients. We aim to determine if the 64-row scanner can also overcome limitations due to mild to moderate calcification. METHODS: Scheduled for conventional coronary angiography, 134 symptomatic patients underwent multidetector CT-assisted angiography within 3 months. Patients were divided into those with low or high calcium score (median score 142) by modified Agatston formula: group A calcium score <142 Agatston score (68 patients, mean age 53 years, heart rate 62 beat/min) and group B calcium score > or = 142 Agatston score (66 patients, mean age 57 years, heart rate 62 beat/min). Eleven major coronary segments were evaluated. RESULTS: In group A, 93.6% of segments were evaluable with 97.3% correlation. Segment-by-segment analyses for sensitivity, specificity, and positive and negative predictive values were 85.4%, 98.1%, 76.7%, and 99.2%, respectively. For group B, 86.9% of segments were evaluable with 90.5% correlation. Sensitivity, specificity, and positive and negative predictive values were 79.9%, 92.8%, 78.8%, and 93.5%, respectively. CONCLUSIONS: The 64-slice multidetector CT coronary angiography can reliably detect the presence of significant coronary stenosis in symptomatic patients with mild calcification, but remains limited by moderate to heavy calcification.

64-row multi-dector computed tomography coronary image from a center with early experience: first illustration of learning curve / 老年心脏病学杂志（英文版）

Background and objectives The recent joint ACCF/AHA clinical competence statement on cardiac imaging with multi-detector computed tomography recommended a minimum of 6 months training and 300 contrast examinations, of which the candidate must be directly involved in at least 100 studies. Whether this is adequate to become proficient in interpretation of coronary computed tomogsignificant coronary stenosis in a center with 1 year's experience using a 64-row scanner. Methods A total of 778 patients underwent contrast-enhanced CTA between January and December 2005. Out of these patients, 301 patients also underwent contrast-enhanced conventional coronary angiography (CCA). These patients were divided into 4 groups according to the time the examination was underwent. Group Q1: first quarter of the year (n=20), Group Q2: second quarter (n=128), Group Q3: third quarter (n=134), and Group Results The sensitivity, specificity, positive, and negative predictive values were Q1 - 64%, 89%, 49% and 94%, respectively; Q2 -79%, 96%, 74% and 97%, respectively; Q3 - 78%, 96%, 74%, 97%, respectively, and Q4 - 100% for all. Conclusions In a center with formal training and high caseload, our accuracy in CTA analysis reached a plateau after 6 months experience. Test-bolus protocols produce better image quality and can improve accuracy. New centers embarking on CTA will need to overcome an initial 6-month learning curve depending upon the caseload during which time they should consider correlation with CCA.