Cardiac Myxoma Associated With Supraventricular Tachycardia as an Unusual Cause of Unilateral Pulmonary Edema

Abstract

A 34-year-old man with sudden palpitations, dyspnea, and chest pain was found to have tachycardia and unilateral pulmonary congestion. Intravenous adenosine restored sinus rhythm. Imaging and pathology confirmed an atrial myxoma with severe mitral regurgitation, requiring surgical excision and mitral valve replacement. This case highlights the complex and rare presentations of cardiac myxomas.

Graphical Abstract

Although cardiogenic pulmonary edema commonly presents bilaterally, cases of unilateral pulmonary edema (UPE) are rare and unusual. When UPE does occur, it is often associated with severe mitral regurgitation (MR). Despite occasional reports, there is limited understanding of UPE, and its prevalence in the broader spectrum of pulmonary edema has not been thoroughly investigated.

Take-Home Messages

• •This case describes an unusual presentation of unilateral pulmonary edema, prompting physicians to consider the underlying causes if they encounter it in their clinical practice.
• •The case highlights the role of atrial myxoma and mitral regurgitation in the pathogenesis of unilateral pulmonary edema and how a supraventricular tachycardia can exacerbate the clinical situation.

The atypical presentation of UPE can sometimes delay diagnosis and treatment, as it deviates from the more familiar bilateral form. This diagnostic challenge underscores the need for a clearer understanding of UPE, including its clinical and echocardiographic features and its impact on patient outcomes.

History of presentation

A 34-year-old man with no medical history, presented to the emergency department with sudden onset of palpitations, dyspnea, diaphoresis, and chest pain. Initial physical examination revealed blood pressure 130/90 mm Hg, heart rate 220 beats/min, respiratory rate 26 breaths/min, oxygen saturation 85% at room air, and Glasgow Coma Scale score of 15. There were crackles on the left lung, the right lung was normal; the rest of the examination was normal. The electrocardiogram showed a regular narrow QRS complex tachycardia (Figure 1). Due to hemodynamic stability, vagal maneuvers were applied but were unsuccessful. Pharmacological cardioversion was needed, intravenous adenosine 6 mg was administered with successful restoring to sinus rhythm (Video 1). The laboratory tests revealed a white blood cell count of 8.3 × 10⁹/L, a creatinine level of 1.6 mg/dL, and B-type natriuretic peptide level of 45 pg/mL. The chest x-ray showed diffused left-sided radio-opacities suggestive of pulmonary congestion and a clear lung on the right side (Figure 2).

Figure 1.

Electrocardiogram Monitoring

Regular narrow QRS complex tachycardia suggestive of atrioventricular nodal re-entrant tachycardia.

Figure 2.

Chest X-Ray

Diffused left-sided radio opacities suggestive of left pulmonary congestion.

Past Medical History

The patient had no significant past medical history.

Differential diagnosis

Differential diagnosis included unilateral pneumonia, broncoaspiration, or alveolar hemorrhaging.

Investigations

While in sinus rhythm, the cardiac auscultation revealed a MR murmur. Transthoracic echocardiogram revealed normal left ventricular size with an ejection fraction of 54%, dilated right ventricle (basal 46 mm, medial 37 mm, and longitudinal 89 mm) with preserved ejection fraction, dilated right atrium (34 mL/m²), pulmonary arterial systolic pressure at 70 mm Hg, dilated left atrium (LA) (58 mL/m²), and a large mobile pedunculated mass approximately 7.5 × 5 cm attached to the middle third of the atrial septum limiting the opening and closure of the mitral valve (Figures 3 and 4, Videos 2 and 3). Additionally, severe mitral and tricuspid regurgitations were observed on Doppler ultrasound (Figure 5).

Figure 3.

Transthoracic Echocardiogram Parasternal Long-Axis View

Showing a huge left echogenic mass (asterisk) filling the left atrium (LA). Ao = aorta; LV = left ventricle.

Figure 4.

Transthoracic Echocardiogram 4-Chamber View

Showing a huge left echogenic mass (asterisk) attached to the atrial septum and protruding through the mitral valve. RA = right atrium; RV = right ventricle; other abbreviations as in Figure 3.

Figure 5.

Transthoracic Echocardiogram Parasternal Long-Axis View With Color Doppler

Showing the mass (asterisk) filling the LA with a moderate degree of mitral regurgitation evident by the presence of mosaic pattern of blood flow during systole (arrow). Abbreviations as in Figure 3.

Transesophageal echocardiography was performed and confirmed the presence of a huge mobile mass filling the LA. It had a heterogenic core of multiple lucent areas and a smooth outer surface suggestive of atrial myxoma.

Management

Twenty-four hours after the pharmacological cardioversion and treatment with IV furosemide, a new chest x-ray was performed and showed normal bilateral lung parenchyma (Figure 6). Due to the high pulmonary artery systolic pressure (70 mm Hg) assessed in the initial transthoracic echocardiogram, we continued performing echocardiographic control after the medical treatment with diuretic agents, the final pulmonary artery systolic pressure was 50 mm Hg before the surgery was performed. The creatinine levels also normalized in the next 5 days (1.0 mg/dL).

Figure 6.

Chest X-Ray

Normal bilateral pulmonary parenchyma.

Subsequently, surgical excision was performed via right atriotomy through the interatrial septum. This revealed a pedunculated mass arising from the interatrial septum at the fossa ovalis; the specimen measured 7.5 × 5 × 4 cm (Figure 7). Elongated mitral chordae tendineae were observed, and the leakage test showed moderate MR. Due to these findings, a valve replacement with a mechanical valve was also needed. The pathology study made the diagnosis of atrial myxoma.

Figure 7.

The Resected Specimen

The specimen measured 7.5 × 5 × 4 cm.

Discussion

Intracardiac tumors are rare, with a global prevalence of approximately 0.02%.¹ Among these tumors, myxomas are the most common, accounting for around 86% of cases.² These tumors have an annual incidence of 0.3 per million people, and most are located in the LA, which is significant due to its potential impact on cardiac function and hemodynamics.

The predominant location of myxomas in the LA may explain their frequent association with embolic and obstructive manifestations, as well as hemodynamic complications. MR is a commonly associated complication with myxomas, as the presence of these tumors can affect the function of cardiac valves and contribute to an additional load on the heart. Chronic MR induces a volume overload in the LA and left ventricle, leading to elevated LA pressure. This elevated pressure is transmitted to the pulmonary venous circulation, potentially causing remodeling, fibrosis, and decreased compliance in the lung, contributing to post-capillary pulmonary hypertension and, eventually, a higher risk of cardiogenic pulmonary edema.³

Cardiogenic pulmonary edema frequently occurs in patients with myxomas due to elevated pulmonary venous pressure and diastolic dysfunction resulting from the myxoma. Acute UPE, which affects 2.1% of the general population,⁴ may be a sign of decompensation in the context of myxomas, especially in the presence of other structural heart conditions. The presence of myxomas can predispose individuals to severe complications such as pulmonary edema, as the tumor can interfere with blood flow dynamics and contribute to heart failure.

Furthermore, supraventricular tachycardias in patients with myxomas can exacerbate the clinical situation, as they may be complicated by thromboembolic, hemorrhagic, and hemodynamic events. Although pulmonary edema associated with supraventricular tachycardias is rare, with a reported incidence of 1% to 3%, its mortality rate can reach up to 18%.³ This suggests that the combination of myxomas and supraventricular tachycardias can be particularly dangerous, especially in patients with underlying heart disease, such as those with myxomas.

In this specific context, and based on a review of the literature on the pathogenesis of unilateral pulmonary edema, 3 factors can combine to explain this case.

First, even if the MR is not acute, when combined with the second factor (the presence of a myxoma), the regurgitant flow can be directed toward the left pulmonary veins, increasing the reflow through the left lung. Additionally, the third factor—supraventricular tachycardia—can diminish diastolic filling time, increasing pressure in the LA and facilitating the transmission of elevated filling pressure through the left lung.

Follow-up

The patient had a good postsurgical recovery and was discharged home 1 week after the surgery with no complications. In the last follow-up, he was completely asymptomatic, under anti-vitamin K treatment.

Conclusions

This clinical case underscores the unusual presentation of a cardiac myxoma, which can be further complicated by supraventricular tachycardias, leading to rare outcomes like in this case of UPE. Despite the general rarity of intracardiac tumors, their potential for complex manifestations necessitates vigilant monitoring and prompt management. The interplay between myxomas and valvular lesions, such as MR, highlights the critical need for comprehensive evaluation in patients with structural heart disease. Early and accurate diagnosis, coupled with targeted treatment, is essential to mitigate risks and improve patient outcomes.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Appendix

Video 1

ECG Monitoring

Supraventricular tachycardia restoring to sinus rhythm after pharmacological cardioversion with adenosine.

Video 2

TTE PLAX View

Showing a huge mobile mass filling the LA and protruding through the mitral valve.

Video 3

TTE 4-Chamber View

Showing a huge left echogenic mass attached to the atrial septum and protruding through the mitral valve.