Frequency and Clinical Significance of Right Atrial Embryonic Remnants Involvement in Infective Endocarditis.

BACKGROUND: The involvement of atrial embryonic remnants in infective endocarditis (IE) has seldom been reported. The study aim was to evaluate the prevalence of vegetations on right atrial embryonic remnants (RAER) in patients with a definitive diagnosis of IE. METHODS: Since 1998, all consecutive patients with suspected IE were referred to the authors' institution to undergo transesophageal echocardiography (TEE). Patients with a high probability of IE but with a negative result underwent a further TEE examination within 10 days. The involvement of RAER was investigated systematically. RESULTS: Among a total of 585 patients evaluated, definitive criteria for IE were present in 210 (35.9%). Right-sided IE was detected in 33 patients (15%); these included 21 infections on the tricuspid valve (65%), 10 cases of intracardiac electronic device infection (29%), one infection on the Thebesian valve (3%), and one on the pulmonary valve (3%). The incidence of right-sided IE was 0.84 per 100,000 population per year. RAER involvement was detected in five patients (15% of right-sided endocarditis), representing 2.5% of the complete IE series. The incidence of RAER endocarditis was 0.13 new cases per 100,000 population per year. The Eustachian and Thebesian valves were involved in four cases. Two patients presented with pulmonary embolism and died in hospital. Transthoracic echocardiography (TTE) allowed the detection of RAER vegetations in two cases. CONCLUSIONS: Although the prevalence of embryonic remnants involvement in IE is underestimated, it may carry an important embolic risk if undetected. As TTE demonstrated only a low sensitivity in the diagnosis of embryonic remnant involvement, TEE should be performed systematically and RAER involvement carefully sought. TEE is recommended in all patients with a high clinical suspicion of right-sided IE. Video 1: Mid-esophageal TEE view. Multiple vegetations attached onto the pacemaker leads (broken arrow) and on the Eustachian valve (solid arrow). Video 2: Mid-esophageal TEE view. A vegetation attached onto the tricuspid valve (broken arrow) and on the Eustachian valve (solid arrow).

Left axillary implantation of loop recorder.

BACKGROUND: We compared the clinical course of 10 patients who received an implantable loop recorder (ILR) at a traditional site with 11 patients whose ILRs were implanted via a subpectoral site via a left axillary approach without complications. METHODS AND RESULTS: R-wave amplitude was determined at implantation and during follow-up. Each patient was followed after 7 days to optimize device setting and then at 1 and 3 months. The R-wave amplitude obtained with the new technique was significantly higher and more stable than that obtained with the standard procedure. Our preliminary experience suggests that axillary access for ILR implantation is feasible, safe, well tolerated, and reliable in terms of sensing function and device performance. Moreover, it is superior aesthetically to the standard approach and carries the potential of minimizing permanent scarring after ILR extraction.

Can right ventricular pacing be useful in the assessment of cavo-tricuspid isthumus block?

BACKGROUND: Cavo-tricuspid isthmus (CTI) block is currently assessed by coronary sinus (CS) pacing or low lateral and septal atrial pacing. Occasionally, CS catheterization through the femoral route can be difficult to perform or right atrial pacing can be problematic because of catheter instability or saturation of the atrial electrograms recorded near the catheter. OBJECTIVES: Our aim was to evaluate the feasibility of assessing cavo-tricuspid isthmus block by means of right ventricular (RV) pacing in patients with ventriculo-atrial conduction, comparing it with CS pacing. METHODS: Circumannular activation was analyzed during CS and RV pacing in consecutive patients in sinus rhythm undergoing CTI ablation for typical atrial flutter. Patients without ventriculo-atrial conduction were excluded from the study. The linear lesion was created during RV pacing and split atrial signals on the ablation line were analyzed. CTI block was confirmed by analyzing local electrograms on the line of block and circumannular activation during CS and RV pacing. RESULTS: Out of 31 patients, 20 displayed ventriculo-atrial conduction (64%) and were included in the study. Before ablation, during RV stimulation, the collision front of circumannular activation shifted counterclockwise in contrast with the pattern observed during CS pacing. After ablation, circumannular activation was similar during CS and RV pacing, showing fully descending lateral right atrium activation, even if double potentials registered on the ablation line were less widely split during RV pacing than CS pacing (111+/-26 ms vs 128+/-30 , p=0.0001). CONCLUSIONS: In patients with ventriculo-atrial conduction, tricuspid annulus activation during CS and RV pacing is similar, before and after CTI ablation. The occurrence of split atrial electrograms separated by an isoelectric interval registered on the line of block can be detected during CS or RV pacing. In patients with difficult CS catheterization via the femoral vein, before trying the subclavian or internal jugular route, if retrograde ventriculo-atrial conduction is present, RV pacing can be an easy trick to assess isthmus block.

Early mobilization after pacemaker implantation.

BACKGROUND: There are no international guidelines indicating how long a patient should stay strictly in bed after pacemaker implantation. In the present study, we tested a new protocol concerning the mobilization of patients 3 h after receiving a single or a dual-chamber pacemaker. METHODS: Consecutive patients who underwent single or dual-chamber pacemaker implantation were randomized to a 3 or 24 h immobilization protocol. Only bipolar passive fixation leads were computed. After the implant, an elastic bandage was put on the homolateral shoulder of all patients for 24 h. A complete clinical and electronic follow-up was performed before discharge and repeated 2 months later. End-points considered were the displacement of the lead, high pacing thresholds (> 3.5 V/0.4 ms at the discharge or > 2.5 V/0.4 ms at the 2-month follow-up), sensing defects not corrigible by programming and clinical complications of the pocket RESULTS: One hundred and thirty-four patients were included in the study: 57 in group A (mobilization after 3 h) and 77 in group B (24 h). In group A, one haematoma and two displacements occurred in three patients. In group B, we registered one haematoma, one subclavian vein thrombosis, three displacements and three high stimulation thresholds. No statistical differences were observed between the end-points of group A versus B. CONCLUSIONS: The present study shows that an early mobilization protocol is feasible because no statistical differences resulted from the two groups of study as regards clinical outcome, complications and electronic measurements of the implanted devices, which have been followed up for 2 months.

Initial energy for biphasic external electrical cardioversion of atrial fibrillation.

BACKGROUND: No international guidelines indicate the initial energy in biphasic external electrical cardioversion of atrial fibrillation (AF) actually. The aim of this study was to determine this value in order to find a reasonable compromise between the necessity of limiting tissue damage and of quickly restoring sinus rhythm as well. METHODS: Fifty-six consecutive patients with AF candidate to external electrical cardioversion were treated using adhesive anterior-posterior paddles and biphasic wave defibrillator Lifepack 12, with steps of 50 J. After 6 hours troponin I levels were measured. RESULTS: Thirty-four patients were cardioverted by 50 J (group A), 18 by 100 J (group B) and 3 by 150 J (group C). One patient was not cardioverted (success rate 98%). No significant differences were noted between groups A and B with regard to age, sex, weight, height, thoracic circumference, body mass index, body surface area, impedance, NYHA class, left ventricular ejection fraction, left atrial diameter, causes of heart disease, antiarrhythmic medications, and duration of current AF episode. No increase of troponin I levels occurred. CONCLUSIONS: An initial shock of 100 J in the biphasic external elective cardioversion of AF is a valid and highly effective option. An initial shock of 50 J was effective in 61% of our population, and it is probably appropriated in patients with a lower weight and body mass index.