A critical review on telemonitoring in heart failure.

Morbidity and mortality remain high in heart failure despite considerable progress achieved with medical therapy and electrical devices. A multidisciplinary approach is actually strongly recommended. In order to provide optimal care to the ever-growing population of patients with heart failure, telemonitoring has been proposed as a modality to improve usual care. The aim of this review is to provide an overview of the existing evidence on telemonitoring in HF. Despite two major meta-analyses with favourable results, two recent, large, multicentre, randomized controlled trials, one with a sophisticated technical remote telemonitoring approach (TIM-HF) in stable chronic HF and the other with a comprehensive telephone-based interactive voice-response monitoring (Tele-HF) in patients recently hospitalized for heart failure, have been performed and both failed to demonstrate a clinical benefit for telemonitoring. Newer technologies or other modalities, such as collaboration between a general practitioner and a heart failure clinic facilitated by telemonitoring should be further evaluated. Dedicated telemonitoring for heart failure may be a practical adjunct in selective centres and patients, on top of usual care, including education and a multidisciplinary approach. However, prior to being accepted as a standard of care, more evidence from large, randomized clinical trials is required.

Is there a potential benefit to increased irrigation channels during radiofrequency ablation? Results from a two-center prospective randomized study.

INTRODUCTION: Open irrigation during radiofrequency (RF) application allows a higher power delivery in the setting of temperature-controlled ablation, without causing blood clots. This study sought to evaluate the clinical value of the additional 6 supplementary channels at the proximal catheter tip compared to a standard irrigated RF catheter with 6 conventional channels present at the distal tip only. METHODS AND RESULTS: Ninety-five consecutive patients were prospectively randomized to cavotricuspid isthmus ablation using an 3.5 mm tip ablation catheter with 6 distal irrigation channels (6C; 48 patients) or an 4 mm tip ablation catheter with 12 irrigation channels (12C; 47 patients) disposed at the distal (6 channels) and proximal (6 additional channels) catheter tip. There was no significant difference between the 12C and the 6C irrigated-tip catheter concerning the total procedural duration, the RF duration, the fluoroscopic duration, and the amount of irrigation. Conversely, there were significantly more patients who experienced at least one steam pop while using the 12C as compared to the 6C irrigated-tip catheter (0% vs 13%, respectively, P = 0.018). CONCLUSION: The addition of proximal irrigation holes at the catheter tip do not facilitate lesion formation during RF ablation, but significantly increases the risk of steam pop. This is probably the consequence of an increase distortion of the temperature feedback.

Complicated forms of tachycardia-mediated cardiomyopathy associated with idiopathic left ventricular tachycardia.

Idiopathic left ventricular tachycardia is an infrequent form of ventricular tachycardia associated with a structurally normal heart. The prognosis is usually benign; however, sustained cases have been reported. In this report, we describe two cases of persistent idiopathic left ventricular tachycardia complicated by tachycardia-mediated cardiomyopathy. In the first case, the patient developed a right ventricular thrombus with subsequent pulmonary embolism. In the second case, the patient developed acute pulmonary edema. Both cases were cured by catheter ablation.

Multidetector 16-slice CT scan evaluation of cavotricuspid isthmus anatomy before radiofrequency ablation.

INTRODUCTION: The anatomy of the cavotricuspid isthmus (CTI) is an important determinant of the ease of radiofrequency ablation. We evaluated the anatomy of the region with a multidetector 16-slice computed tomography (CT) scan and correlated this with subsequent procedural difficulty. METHODS: Twenty-nine patients (mean age 64 +/- 15 years) with typical atrial flutter or paroxysmal atrial fibrillation underwent ablation of the CTI. A multidetector 16-slice CT scan with contrast injection was performed in all before the procedure. RESULTS: The CTI showed marked variability as evidenced by the following measurements: length (8.2 to 32.2 mm), width (26 to 56.5 mm), depth (0 to 11 mm), thickness (0.2 to 7.5 mm), the angle between the inferior vena cava and the CTI (59.9 to 129.5 degrees ), and the length of the Eustachian valve (4.8 to 26.1 mm) present in 72% of patients. The appearance of the CTI was classified as follows into three categories: concave (72%), flat (17%), or with a sub-Eustachian recess (28%). Procedures were classified as difficult in case of failure to achieve bidirectional block or if radiofrequency duration was greater than 99% confidence interval. In the multivariate analysis, a significant correlation was present between the thickness of the CTI and procedural difficulty (p = 0.0005). CONCLUSIONS: The multidetector 16-slice CT scan with contrast injection accurately evaluates the anatomy of the CTI. The only independent anatomic parameter that predicts a more difficult procedure is the thickness of the CTI.