Right Ventricular Hypertrophy Case Studies

Case 1: Obstructive lung disease

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Obstructive lung disease (COPD), commonly caused by smoking, increases the pulmonary resistance to blood flow from the pulmonary artery. When the resistance to blood flow rises, the pressure builds up in the right ventricle. The increased pressure must be generated by the right ventricle, which hypertrophies to meet the new increased workload. The right atrium eventually becomes involved, as the right ventricle struggles to meet its new burdens. The EKG shows RVH and RAA (Figure 18.11). COPD traps a large volume of air inside the lungs. This air is a terrible conductor of electricity and interferes with the recording of the EKG. This can cause low voltage to appear on the EKG (Figure 18.11).

COPD reduces the cross-sectional area of blood flow through the lungs (Figure 18.10). This increases the pressure in the pulmonary artery, which the right ventricle must match and exceed, or the pulmonary valve would never open. The right atrium hypertrophies as well to assist the right ventricle meet its new workload.

When the level of trapped air gets severe, the EKG shows low voltage (Figure 18.11). If the sum of the QRS amplitude in leads I, II, and III is less than 15 little boxes, low voltage is present. If none of the QRS complexes in leads V1, V2, or V3 is 15 little boxes by itself, then low voltage is present.

Case 2: Pulmonary embolism

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Pulmonary embolism is usually part of a disease process termed venous thromboembolism (VTE). Because of a hypercoagulable state, trauma to a blood vessel, or low flow states, a thrombus can form in the venous system and then embolize to the pulmonary artery. Pulmonary embolism can develop as a single event, but it can also become recurrent. The embolus in the pulmonary artery obstructs blood flow to part of the lungs and increases the pressure behind the clot. The right ventricle typically dilates rapidly in response to this. In the acute setting, the EKG can (but may not) demonstrate sinus tachycardia, RVH, and RAA.

If the pressure overload is severe, there can be a supply and demand mismatch for the right ventricle, and abnormal T waves can result. The EKG can show a T axis that points posterior, not away from the septum, but away from the free wall of the right ventricle, as illustrated in Figures 18.2 and 18.3. When the T wave is downward in V1, V2, and V3, the cause may be ischemia or infarction of the septum OR pulmonary embolism.

The presence of an S wave in lead I, with a Q wave and inverted T wave in lead III is called SIQTIII (Figure 18.12), and is classic for pulmonary embolism.

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Right Ventricular Hypertrophy Case Studies

Table of Contents

Case 1: Obstructive lung disease

Case 2: Pulmonary embolism