Long‐term study on electrophysiological characteristics and catheter ablation of idiopathic ventricular arrhythmias originating from the left ventricular posterior papillary muscles guided by intracardiac ultrasound

Figures

• 

  FIGURE 1. Shown were the ECG characteristics. Cases 1 and 2 were PVC and VT cases of LPPM origin, and cases 3 and 4 were PVC and VT cases of LPF origin. All are right bundle branch block patterns. Lead I was rS or Rs type, the main wave of inferior wall lead (II, III, and aVF) was mainly negative, aVR lead was characteristic qR type, and AVL lead was mainly positive. The most important difference between the two groups was that the left “rabbit ear” sign was common in V1 of the LPPM group and the right “rabbit ear” sign in V1 of the LPF group. The origin of LPPM shifts from precordial leads V2 to V4. R ‘waves were often seen in leads V3, whereas deeper S waves were seen in leads V5 and V6

• 

  FIGURE 2. Shown were the different papillary muscle morphologies. The left, middle, and right figures show the different forms of the left posterior papillary muscle; single head, double heads, and triple heads (at the arrow)

• 

  FIGURE 3. Shown was the bipolar potential at the target. Cases 1 and 2 were PVC and VT cases of LPPM origin, and cases 3 and 4 were PVC and VT cases of LPF origin. In the LPPM group, a sharp potential, similar to a bundle branch potential or “papillary muscle potential,” can be seen at the effective ablation target. In the LPF group, the bundle branch potential (P potential) was constant in front of the V wave

• 

  FIGURE 4. Morphology of QRS wave during pacing papillary muscle. (a, b and c) represented pacing at the bottom, end, and top of papillary muscle base respectively. It could be seen that the QRS waveform state of ECG during pacing was consistent with that of primary premature beat. It was suggested that there was no significant difference in QRS wave morphology during pacing for ventricular premature beats originated from different parts of the same papillary muscle head, so pacing mapping was not suitable for papillary muscle ventricular arrhythmia mapping