ight heart failure because of tricuspid regurgitation (TR) after permanent pacemaker (PPM) has been reported. [1][2][3][4][5][6] Conventional 2-dimensional (D) echocardiography (echo), though very important for detecting TR, is quite limited in depicting the precise anatomical relationship between the tricuspid leaflets and PPM lead shaft. 2 This relationship may determine the pathogenesis of TR and realization of it may help determine the policy of management. In this report, with the assistance of 3D echo, the structure of the tricuspid valve, its incompetence and the entrapment of the PPM lead shaft in the valve were precisely delineated. Case ReportA 58-year-old man underwent implantation of a transvenous VVIR PPM for atrial fibrillation and complete heart block 9 years ago. Prior to PPM, echocardiography showed moderate TR, with a TR area of 16.6 cm 2 and a right atrial (RA) area of 28.8 cm 2 , and normal systolic function of both ventricles. Three years after PPM implantation, 2D echo showed aggravation of TR with a TR area of 19.4 cm 2 and a RA area of 37.4 cm 2 . Since then, he had abdominal fullness and edema of both legs. These symptoms gradually became aggravated. Follow-up transthoracic echocardiography was performed by using a Philips SONOS 7500 (Philips Medical Systems, Eindhoven, Netherlands) and pyramid-shaped full-volume 3D images of the right ventricle (RV) were acquired from between the left parasternal border and the apical window with a 4 MHz and 4× matrix transducer under ECG gating while the patient gently held his breath. The 2D echo revealed slightly impaired systolic function of the left ventricle with abnormal septal wall motion and mild Circulation Journal Vol.71, July 2007 mitral regurgitation. The RV, RA and inferior vena cava were dilated, and RV function was normal (Fig 1A). Tethering of the septal leaflet of tricuspid valve was observed, together with no coaptation of thes leaflets, thus causing severe TR (Fig 1B). The maximal area of TR was 42.1 cm 2 and that of RA 64.6 cm 2 . The transtricuspid systolic pressure gradient was 12 mmHg. However, the relationship between the tricuspid valve and the PPM lead could not be observed on the multiple views of 2D echo (Figs 1C,D).After being cropped in from the apex toward the base, the full-volume 3D echo showed that the shaft of the PPM lead was entrapped in the thickened, fibrotic and fused posterior and septal leaflets (Fig 2A), which could not coapt during systole, and the vena contracta was well seen (Fig 2A, arrowhead). During diastole, the anterior tricuspid leaflet opened freely. The anterior two-thirds of the septal leaflet was tethered, but not fixed, and could be pushed open slightly. The remaining one-third of the septal leaflet and the entire posterior leaflet was thickened, tethered and frozen (Fig 2B). When the full-volume 3D pyramid was cropped in from the RV free wall, the entrapment of the PPM shaft in the fused septal and posterior leaflets and the free movements of anterior tricuspid leaflet were noted clearly during ...

The proposed DNN-based method can achieve reliable S1 and S2 recognition performance based on acoustic characteristics without using an ECG reference or incorporating the assumptions of the individual durations of S1 and S2 and time intervals of S1-S2 and S2-S1.

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