# A Rare Incidental Discovery of an Intrapulmonary Shunt in a Young Man: A Case Report

## TL;DR

A 21-year-old man had an unexpected discovery of an intrapulmonary shunt, showing the importance of timing in bubble studies for accurate diagnosis.

## Contribution

Highlights the importance of bubble study timing in distinguishing intrapulmonary shunts from intracardiac shunts in young patients.

## Key findings

- No bubbles appeared in the left atrium during the first six cardiac cycles.
- Bubbles appeared in the left atrium and ventricle after six cycles, indicating an intrapulmonary shunt.

## Abstract

An intrapulmonary shunt (IPS) occurs when blood bypasses oxygenation in the lungs, flowing directly from the right side of the heart to the left side without undergoing gas exchange. This condition is distinct from an intracardiac shunt, which involves an abnormal connection between the heart chambers or vessels, allowing atypical blood flow. In this report, we present the case of a 21-year-old man with a one-year history of persistent cough, nocturnal chest pain, nasal congestion with shortness of breath, and generalized abdominal pain. In the emergency department, his vital signs and physical examination were unremarkable. Electrocardiography (EKG) revealed sinus bradycardia with right-axis deviation and incomplete right bundle branch block pattern. Chest X-ray and routine laboratory investigations were normal. The patient was referred to cardiology for further evaluation of shortness of breath. A transthoracic echocardiogram (TTE) with a bubble study demonstrated a normal ejection fraction of 63% with no regional wall motion abnormalities. Agitated saline injected via the left antecubital vein revealed no bubbles in the left atrium during the first six cardiac cycles. However, after six cycles, a small number of bubbles appeared in the left atrium and left ventricle, indicative of an IPS. In this case report, we highlight a unique incidental finding of an IPS in a young man, emphasizing the importance of bubble study timing in distinguishing IPS from intracardiac shunts.