Search

Atrial fibrillation (AF) is the most common type of arrhythmia, and is characterized by a disordered contractile activity of the atria (top chambers of the heart). A popular treatment for AF is radiofrequency (RF) ablation. In about 2.4% of cardiac RF ablation procedures, the catheter is accidently pushed through the heart wall due to the application of excessive force. Despite the various capabilities of currently available technology, there has yet to be any data establishing how cardiac perforation can be reliably predicted. Thus, two new FBG based sensor prototypes were developed to monitor contact levels and predict perforation. Two live sheep were utilized during the study. It was observed during operation that peaks appeared in rhythm with the heart rate whenever firm contact was made between the sensor and the endocardial wall. The magnitude of these peaks varied with pressure applied by the operator. Lastly, transmural perforation of the left atrial wall was characterized by a visible loading phase and a rapid signal drop-off correlating to perforation. A possible pre-perforation signal was observed for the epoxy-based sensor in the form of a slight signal reversal (12-26% of loading phase magnitude) prior to perforation (occurring over 8 s). [ABSTRACT FROM AUTHOR]

The article describes the case of a myocardial noncompaction and congenital absence of pericardium. A 58-year-old man with dyspnea on exertion, a low left ventricular ejection fraction, and an abnormal nuclear stress test was observed to have abnormal orientation of the heart during cardiac catheterization.

Permanent junctional reciprocating tachycardia, or atrioventricular reentrant tachycardia utilizing a slowly conducting posteroseptal accessory pathway, is a rare form of reentrant supraventricular tachycardia in children and adults. The characteristic features of this narrow complex tachycardia are a long RP interval and inverted P waves in the inferior leads. This form of accessory-pathway-mediated tachycardia, which is usually incessant, can lead to a tachycardia-induced cardiomyopathy and congestive heart failure if left untreated. Radiofrequency ablation of the accessory pathway in permanent junctional reciprocating tachycardia is the definitive treatment in these patients, and in many instances the effects of prolonged tachycardia on ventricular function are reversible after successful ablation. We present an illustrative case. [ABSTRACT FROM AUTHOR]

Background: The main aim of our study was to investigate the influence of calcification on the accuracy of 64-slice computed tomography for identification of significant coronary artery disease. Methods: A contrast-enhanced 64-slice computed tomography was performed prior to invasive coronary angiography in 168 consecutive patients with suspected coronary artery disease. All coronary segments 1.5 mm or larger in diameter were evaluated for the presence or absence of significant coronary artery stenosis, defined as a diameter reduction of >50%. The patients were also ranked by total calcium score which was expressed in Agatston units and the impacts of calcification on diagnostic accuracy of 64-slice computed tomography were assessed. Results were compared with quantitative coronary angiography as the standard of reference. Results: The overall sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice computed tomography for detection of significant stenosis were: by segments, 95%, 98%, 91%, and 99%, respectively; by patient, 98%, 97%, 96%, and 99%, respectively; and by artery, 94%, 93%, 91%, and 95%, respectively. In mild and moderate calcium scores (0 - 418 Agatston units), the sensitivity was 100%, specificity was 93%, positive predictive value was 97% and negative predictive value was 100%. Severe calcification (>419 Agatston units) reduced the sensitivity, specificity, positive, and negative predictive values of multi-slice computed tomography to 89%, 60%, 89%, and 60%, respectively. Conclusion: Our study revealed that the 64-slice computed tomography is a highly accurate diagnostic modality for detecting hemodynamically significant coronary stenosis; however, severe calcification is considered as a shortcoming which limits the routine application of multi-slice computed tomography in daily practice. [ABSTRACT FROM AUTHOR]