Final Feigenbaum’s Echocardiography DIGITAL

Feigenbaum’s Echocardiography

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Feigenbaum’s Echocardiography

motion abnormality similar to that seen in native le bundle branch block. Many of the same rules regarding preservation of thicken- ing and of late systolic endocardial motion discussed previously also pertain to evaluating wall motion in the presence of a paced rhythm. Because most endocardial pacing leads are placed apically, the location of maximal abnormality previously referred to is far less helpful. On occasion, a ventricular pacing lead can be in the more inferior portions of the distal septum and result in a distal inferior wall motion abnormality (Fig. 5.49). Separation of this wall motion abnormality from that due to true ischemia can occasionally be problematic. It has become standard therapy to use biventricular pacing for mechanical resynchronization in patients with underlying conduction system disease (typically le bundle branch block) and systolic dysfunction. Resynchronization, via simultaneous biven- tricular pacing, results in more eƒcient mechanics of ejection and improved cardiovascular performance.…e appearance of regional wall motion abnormalities in these patients will be highly variable and dependent on underlying conduction and the relative contribu- tions of the two pacing sites. Caution is advised when attempting to diagnose an ischemic wall motion abnormality in this setting. Pericardial Constriction Pericardial constriction results in a variety of wall motion abnormal- ities.…e underlying reason for the abnormalities is exaggerated dif- ferential ˆlling and contraction of the right and le ventricles.…is alters the sequence and magnitude of septal position and motion. Superimposed on the beat-to-beat abnormality of septal motion can be exaggerated respiratory variation in septal position related to increased ventricular interdependence. Initial descriptions of abnormal wall motion in constrictive pericarditis were based on M-mode echocardiography, and one or two septal and posterior wall motion abnormalities were described as “typical” (Fig. 5.50). It quickly became apparent that there was a broad range of septal motion abnormalities, all of which resulted in an early downward FIGURE 5.49. Apical two-chamber view recorded in a patient with a right ventricular trans- venous pacemaker. In the M-mode echocardiogram, notice the atypical pattern of septal motion consistent with a bundle branch block. In the apical two-chamber view, note the marked inferoapical wall motion abnormality in this patient, known to be free of coronary artery disease, related to pacing at the inferoapical aspect of the right ventricle.

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FIGURE 5.47. M-mode echocardiogram recorded in a patient with ventricular bigeminy. The upper panel was recorded during bigeminy and reveals an abnormal contraction pattern of the ventricular septum ( arrow ) coincident with the PVC. The internal dimension in diastole and systole for the post-PVC beat is noted from which a fractional shortening of 0.45 is cal- culated. The lower panel was recorded in the same patient during an arrhythmia-free period. Note the normal contractile pattern of the septum and posterior wall and the consistent fractional shortening of 0.33. The increased fractional shortening in the post-PVC beat is related to hyperkinetic motion following a post-PVC pause. Ventricular Pacing …e majority of ventricular-paced rhythms are done with apically located right ventricular endocardial leads.…is results in a le bundle branch block pattern on the electrocardiogram, and a wall

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FIGURE 5.48. Continuous-wave Doppler in a patient with aortic stenosis and reduced left ven- tricular systolic function, demonstrating the impact of a PVC on left ventricular contractility. The central continuous-wave Doppler is a continuous recording. Note the PVC ( upward-pointing arrow ), after which there is a modest postcompensatory pause. The post-PVC beat has aug- mented contractility and stroke volume. This results in an increased aortic valve peak gradient of 71 mm Hg and a mean gradient of 40 mm Hg. The panel at the upper right was recorded during regular sinus rhythm at which time there was a stable peak gradient of 33 mm Hg and a mean gradient of 20 mm Hg. The numeric data at the upper left depict the gradient for the post-PVC beat in the upper portion and for the normal sinus rhythm in the lower portion.

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