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The Echo Manual

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CHAPTER 12 PERICARDIAL DISEASES

systole. Compared to RA diastolic collapse, RV collapse in early diastole is very specific for tamponade. Diastolic compression of the right heart may be absent if right- heart pressure is elevated. Left atrial (LA) chamber col- lapse is uncommon but very specific for tamponade, and LV collapse is rare. Abnormal ventricular septal motion results from respiratory variation in ventricular filling (see discussion below). Plethora of the inferior vena cava with impaired inspiratory compression indicates elevated RA pressure from high intrapericardial pressure, but a subset of the patients with clinical tamponade may lack IVC plethora and inspiratory compression. (Miranda et al. Unpublished observation). With acute myocardial rupture or proximal aortic dis- section, echodense clotted blood (hemopericardium) may accumulate in the pericardial sac; this finding is called coagulum tamponade (Fig. 12-9). When air devel- ops in the pericardial sac (pneumopericardium) as a result of esophageal perforation, transthoracic and TEE are difficult because ultrasound does not penetrate air well, but localized pneumopericardium has a characteris- tic appearance (Fig. 12-9). The Doppler echocardiographic findings of pericardial effusion with hemodynamic compromise are more sensi- tive than the 2D echocardiographic features mentioned above (15,16). They result from changes in the left ventricu- lar filling gradient mediated by respirophasic intrathoracic pressure changes and amplified by increased ventricular interdependence, or increased dependence of LV filling on RV filling (and vice versa) within the relatively fixed total cardiac volume (17). Similar to constrictive pericarditis Q7

FIGURE 12-8 ( Continued ) C: Top , Parasternal long-axis views during systole and diastole of a patient with tamponade. During early diastole, the RV-free wall col- lapses ( arrows at top ). LA , left atrium; VS , ventricular septum; LV , left ventricle; RV , right ventricle. Bottom , Apical four-chamber view demonstrating late diastolic collapse of right atrial ( RA ) wall ( arrow ). This sign is sensitive but not specific for tamponade. When RA inversion lasts longer than a third of the RR interval, it is specific for tamponade.

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FIGURE 12-9 Left: A subcostal view showing echodense gelatinous mass ( arrows ) in the pericardial sac characteristic for hemopericardium (Video 12-4). Right: Bright echoreflection ( arrows ) in the pericardium characteristic for pneumoperi- cardium in a patient with gastropericardial fistula. LA , left atrium; RA , right atrium; RV , right ventricle.

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