Chapter 3: Cardiac ultrasound
An apical 4 chamber view is remarkable for an apical septal and apical lateral wall motion abnormality (dyskinetic segments) in a patient with acute myocardial infarction. Note that the base of the left ventricle appropriately thickens and contracts during systole whereas the apical segments are thin and move in the opposite direction.
A parasternal long axis view in a patient with dilated cardiomyopathy and severely depressed ejection fraction (EF). Note that the walls of the LV are thin and poorly contractile, and there is little change in the internal diameter of the LV between systole and diastole. Also, during diastole, the anterior leaflet of the mitral valve (AML) remains distant from the interventricular septum (IVS), a sign of reduced forward flow velocities across the mitral valve. This distance can be quantified in M-mode and is known as E-point septal separation (EPSS). An EPSS greater than 7 mm is suggestive of depressed EF in the absence of significant valvular abnormalities, and may lead the emergency physician toward inotropic support in patients with undifferentiated hypotension.
A subxyphoid view in a patient with stab wound to the chest who lost vitals en route to a level 1 trauma center demonstrates hemopericardium. Although the patient was diagnosed with pulseless electrical activity (PEA) arrest, weak cardiac contractility was appreciated on his bedside ultrasound. Note that both the visceral and parietal pericardium are hyperechoic and well defined, and an echogenic pericardial clot is interspersed between them that moves with the cardiac cycle. A potential pitfall for novice sonographers is that pericardial clot may be mistaken for liver parenchyma because of similar echogenicity.
A parasternal long axis view of a patient with hypotension and electrical alternans is remarkable for a large circumferential pericardial effusion and diastolic collapse of the right ventricle, consistent with pericardial tamponade. Note the swaying of the heart in the pericardial sack, which visually demonstrates the phenomenon of electrical alternans seen on his electrocardiogram.
On subxphoid view, tamponade is again evident as the heart, surrounded by large circumferential pericardial effusion, sways violently about its axis. The patient underwent emergent pericardiocentesis under ultrasound guidance with immediate improvement in hemodynamics.
In this clip of a patient with cardiac arrest after penetrating chest trauma, cardiac standstill with hemopericardium is initially apparent. The bedside ultrasound demonstrates evacuation of the pericardial clot and return of cardiac contractility and spontaneous circulation in real time.
Subxyphoid view of patient that presented to the emergency department with an unstable bradycardia. Bedside ultrasound was utilized in this case to guide and confirm proper placement of a transvenous pacemaker. In real time, a hyperechoic pacing wire with reverberation artifact can be seen entering the right ventricle (RV). A moderate sized pericardial effusion is also apparent.