Prevalence of conduction delay of the right atrium in patients with SSS: implications for pacing site selection.

OBJECTIVES: To evaluate the prevalence of severe right atrial conduction delay in patients with sinus node dysfunction (SND) and atrial fibrillation (AF) and the effects of pacing in the right atrial appendage (RAA) and in the inter-atrial septum (IAS). METHODS: Forty-two patients (15 male, 72 +/- 7 years) underwent electrophysiologic study to measure the difference between the conduction time from RAA to coronary sinus ostium during stimulation at 600 ms and after extrastimulus (DeltaCTos). Patients were classified as group A if DeltaCTos > 60 ms and group B if < 60 ms. Each Group was randomized to RAA/IAS pacing and algorithms ON/OFF. RESULTS: Fifteen patients (36%, group A) had DeltaCTos = 76 +/- 11 ms and 27 patients (64%, group B) had DeltaCTos = 36 +/- 20 ms. Twenty-two patients were paced at the RAA and 20 at the IAS. During the study, no AF recurrences were reported in 11 of 42 (26%) patients, independently of RAA or IAS pacing. Patients from group A and RAA pacing had 0.79 +/- 0.81 episodes of AF/day during DDD, which increased to 1.52 +/- 1.41 episodes of AF/day during DDDR + Alg (P = 0.046). Those with IAS pacing had 0.5 +/- 0.24 episodes of AF/day during DDD, which decreased to 0.06 +/- 0.08 episodes of AF/day during DDDR + Alg (P = 0.06). In group B, no differences were reported between pacing sites and pacing modes. CONCLUSIONS: Severe right atrial conduction delay is present in one-third of patients with SND and AF: continuous pacing at the IAS is superior to RAA for AF recurrences. In patients without severe conduction delay, no differences between pacing site or mode were observed.

Transoesophageal echocardiographic evaluation of pulmonary vein anatomy in patients undergoing ostial radiofrequency catheter ablation for atrial fibrillation: a comparison with magnetic resonance angiography.

OBJECTIVE: A detailed definition of pulmonary vein (PV) anatomy is of great importance in patients undergoing radiofrequency catheter ablation for atrial fibrillation. In fact, it is known that variations in the number and anatomy of the PV ostia are more frequent than thought. The aim of this study was to assess the usefulness of transoesophageal echocardiography (TOE) in defining the exact PV anatomy by comparing it with magnetic resonance angiography (MRA), which is proven to be very accurate. METHODS: Forty-five consecutive patients (39 male, 6 female, mean age 50 + or - 6 years) affected by drug-refractory atrial fibrillation underwent radiofrequency catheter ablation. They were all studied with MRA and then with TOE in order to exclude intra-atrial thrombi and to assess PV anatomy. RESULTS: TOE visualised the superior PVs in 100% of cases and the right and left inferior PVs in 98% and 94% of cases, respectively. Only 19 patients (42%) showed typical PV anatomy, with two left and two right distinct PV ostia. In 14 patients (31%), one or two intermediate right PVs and in 12 patients (27%) a common left trunk were detected. The concordance with MRA was high (95%). CONCLUSIONS: TOE is accurate in assessing PV anatomy and in showing anatomic variations in the PV ostia compared with MRA. Anomalous pulmonary venous drainage is more frequent than expected. TOE can provide functional Doppler information, thus being particularly useful in the follow-up after radiofrequency catheter ablation.

Unusual tumor-like calcification of the mitral annulus: diagnosis and tissue characterization by ultrasound, computed tomography and magnetic resonance imaging.

Calcification of the mitral annulus is a common echocardiographic finding in the elderly, particularly in females. Calcium deposits are generally located in the posterior mitral ring, sometimes extending to the whole mitral annulus and involving the mitral valve apparatus. The present report refers to 2 patients with a very atypical mass-like calcification of the mitral annulus resembling a cardiac tumor. A detailed evaluation of the mass was obtained at transthoracic and transesophageal echocardiography; the differential diagnosis with other intracardiac masses was aided by the use of computed tomography and magnetic resonance imaging. To our knowledge there has been no prior report of such a lesion evaluated at cardiac magnetic resonance imaging.