Trong hầu hết các trái tim bình thường bó thời gian phục hồi phải dài hơn so với gói trái, nhất dị thường, do đó, có một hình thái RBBB. PAC kết quả trong nhịp đập non, nhưng PAC đầu cuối có thể bắt đầu một nhịp tim nhanh kịch phát. | A. 1st degree AV block B. PACs C. PVCs D. PVCs with fusion E. PJCs Answer B These PAC s indicated by arrows enter the ventricles and find the right bundle refractory. They therefore conduct with RBBB aberrancy. In most normal hearts the right bundle recovery time is longer than the left bundle s most aberrancy therefore has a RBBB morphology. Late PACs result in premature beats but early PACs can initiate a paroxysmal tachycardia. Q4 Using calipers don t poke the monitor what type of pause do you see after this funny looking premature beat A. Complete compensatory pause B. incomplete compensatory pause C. No pause next beat is on time D. Interpolated pause E. None of the above Answer A The distance between the P waves before and after the PVC is the same distance as two P cycles elsewhere in the rhythm strip. This implies that the sinus node was not reset and that the fu nny looking beat is a PVC. As a side note this PVC occurs on the peak of the T wave of the preceeding beat making it an R on T. 11 Q5 Using calipers what type of pause do you see after either of these two premature beats A. Complete compensatory pause B. Incomplete compensatory pause C. No pause next beat is on time D. Interpolated pause E. None of the above Answer B PAC s are identified by the arrows. Note that the PP interval surrounding the PAC is less than 2x the basic sinus cycle indicating that the sinus node has been reset by the ectopic P wave. The pause after the PAC therefore is incomplete. An incomplete pause suggests a PAC although there are exceptions . Q6 Choose from the following responses to interpret this ECG. A. PJC Premature junctional complex B. Atrial flutter C. Atrial fibrillation D. AV nodal reentrant tachycardia E. Accelerated junctional rhythm Answer C Atrial fibrillation is characterized by an irregularly irregular ventricular response and the absence of discrete P waves. In the top lead in this ECG atrial activity is poorly defined. The atrial activity seen in the lower .
