Unusual presentation of a patient with partial anomalous pulmonary venous connections without a septal defect: a case report and literature review

Abstract

Introduction

Partial anomalous pulmonary vein connections (PAPVC) are rare congenital abnormalities in which one or more pulmonary veins drain into the right atrium. This pathological condition may present in various ways, such as chest pain and dyspnea, or it may be diagnosed incidentally. Consequently, missed or late diagnoses are common, highlighting the importance of optimal diagnostic modalities. This study presents a case of PAPVC that remained undiagnosed despite two years of symptomatic evaluations.

Case Presentation

The patient was a 58-year-old woman who presented with chest pain and dyspnea, New York Heart Association Functional Class (NYHA FC) II, which had started 2 years before. She had been evaluated with a transthoracic echocardiogram, coronary angiography, and chest imaging, none of which resulted in a diagnosis or effective treatment. After being referred for evaluation by a cardiac imaging specialist, the diagnosis of PAPVC was revealed. The patient underwent corrective surgery, resulting in complete recovery and symptom improvement. Post-surgical cardiac overload caused pleural effusion and dyspnea, which were managed with diuretics. Four- and six-month follow-ups showed no abnormal findings on examination and imaging, and the patient reported no new complaints.

Conclusion

The findings in this structural cardiac abnormality are nonspecific and can be missed, and misdiagnosis is relatively common. However, patients with symptoms such as chest pain, dyspnea, increased pulmonary artery pressure, and right ventricle dilation should undergo surgical treatment to avoid more serious complications, such as heart failure.

Key clinical point

Detection of PAPVC is not straightforward in many cases and often requires evaluation with various imaging techniques for accurate diagnosis. Therefore, physicians encountering undefined causes of chest pain or dyspnea should consider multiple imaging modalities. Follow-up is also important, as certain groups of patients may require surgical treatment to prevent complications.

Introduction

Partial Anomalous Pulmonary Vein Connections (PAPVC) are rare congenital defects in which one or more pulmonary veins drain into the right atrium or its tributaries. Different types have been observed in 0.5-1% of autopsies. However, fewer presentations throughout a patient’s lifetime are largely attributed to the asymptomatic condition. This anomaly often results in a left-to-right shunt (LTRS), which may require surgical correction. Another reason for fewer presentations is that the diagnosis is not straightforward and may require multimodality imaging [1]. Based on the drainage location, it can be categorized into four groups: supra-cardiac, cardiac, infra-cardiac, and mixed-type [2]. This condition might be isolated or occur with other concomitant structural disorders such as an atrial septal defect (ASD) [3]. Both lungs are involved in very rare variations of PAPVC [4]. A dual drainage variation of PAPVC, similar to Total Anomalous Pulmonary Vein Connections (TAPVC), occurs when the pulmonary veins drain into systemic veins at two different levels, most commonly at the cardiac and supra-cardiac levels [5]. Treatment depends on the clinical and hemodynamic condition and findings from cardiac imaging evaluations. While some patients are asymptomatic and may live without intervention, others may require immediate surgical or transcatheter interventions to prevent serious complications [67]. Although there is a trend toward transcatheter correction of the anomaly, surgical treatment remains the gold standard for treating PAPVC [8].

This study presents a patient with undiagnosed chest pain for two years despite several evaluations, who was finally diagnosed as PAPVC after being referred for TEE and PCTA. This case, in addition to highlighting the existence of this rare condition, underscores the importance of comprehensive evaluation of undiagnosed cases with cardiac or respiratory complaints and referral to more specialized centers when necessary.

Case presentation

History and physical examination

The patient is a 58-year-old woman who presented to a tertiary cardiology center with ongoing and progressive dyspnea, which began as exertional dyspnea 2 years ago and worsened over time. Two weeks ago, she experienced breathlessness and severe chest pain at rest. The patient reported a history of a complete cardiology workup in their town, which was inconclusive and did not result in any definitive diagnosis. The patient also had a history of uncontrolled blood pressure and poor adherence to antihypertensive therapy. She was taking a combination tablet of Valsartan (160 mg) and Amlodipine (5 mg) twice daily, Aspirin (81 mg) daily, and Atorvastatin (40 mg) each night.

During her physical examination, her general appearance was anxious. On vital sign examination, the respiratory rate was elevated (22/minute); the oxygen saturation on room air was also measured to be 98%, and her blood pressure in both arms was 170/100 mmHg in a supine position. The patient was not febrile. The respiratory physical examination showed no abnormalities. On the other hand, the cardiac examination raised concern for cardiac abnormalities due to the presence of fixed S2 splitting on cardiac auscultation, which prompted a plan for temporary admission and further evaluation, including an electrocardiogram (ECG), transthoracic echocardiogram (TTE), and a probable transesophageal echocardiogram (TEE).

Diagnostic and therapeutic procedures

The patient’s ECG showed no abnormal findings. (However, TTE revealed Right ventricular dilation and dysfunction without any other abnormalities. The QP/ QS ratio was 2.1. Other significant findings on TTE included marginally increased pulmonary arterial pressure (PAP), moderate tricuspid regurgitation (TR), and Mild to moderate pulmonary valve insufficiency (PI) (Table 1).

Table 1 Findings of initial transthoracic echocardiogram

TEE examination revealed that the upper right pulmonary vein appeared anomalous and drained into the superior vena cava (SVC). (Fig. 1) Given the dilated right ventricle observed on TEE, more than one pulmonary vein was suspected to be involved. Following American Heart Association (AHA) guidelines, the patient underwent a pulmonary CTA, which revealed that two pulmonary veins were affected. The right upper lobe (RUL) pulmonary vein drained into the SVC, and the left pulmonary vein drained into the brachiocephalic vein—findings consistent with PAPVC (Fig. 2). The sagittal plane also showed a vertical vein that abnormally connected the left pulmonary vein to the left brachiocephalic vein (Fig. 3). She underwent surgery, during which the presence of the second anomalous vein was confirmed, validating the conclusions of the CTA. The coronary arteries appeared normal on the CAG. The videos of axial, coronal, and sagittal views are attached to the manuscript (Supplementary videos 1, 2 and 3).

Fig. 1

Left: Color study TEE with an upper esophageal view illustrates flow (green arrow) from RUPV (blue) to SVC (orange). The red arrow indicates the ascending aorta; right: Contrast study with the upper esophageal view highlights the ascending aorta (green arrow), the SVC filled with contrast (red arrow), and negative contrast (yellow arrow) caused by flow from the RUPV (blue arrow)

Fig. 2

A: The chest computed tomography angiography in the coronal plane reveals abnormal pulmonary vein connections. The vertical vein (white arrow) connects the left pulmonary vein to the left brachiocephalic vein (orange arrow). The right upper pulmonary vein (blue arrow) also connects to the superior vena cava (red arrow). The green arrow highlights the mixture of blood and dye at the site of the connection. B: The axial plane at the ventricular level shows an intact interatrial septum and significant right atrium and ventricle dilation. C: The axial plane at the superior vena cava level reveals an abnormal connection of the right upper pulmonary vein to the superior vena cava, indicated by the blue arrow and red arrow, respectively, resulting in a mixture of blood and contrast. D: The coronal plane shows an abnormal connection between the right upper pulmonary vein (blue arrow) and the superior vena cava (red arrow)

Fig. 3

The chest computed tomography angiography in the sagittal plane shows a vertical vein (blue arrow) that abnormally connects the left pulmonary vein (red and green arrows) to the left brachiocephalic vein

The surgery was successful, and the patient was transitioned from the care of cardiology and cardiac surgery services to the ICU.

The patient showed poor cooperation with deep breathing exercises and was unwilling to move. Within 24 h after surgery, the patient experienced reduced oxygen saturation (79%) and dyspnea caused by postoperative lung atelectasis. A series of diagnostic tests, including a chest CT, chest X-ray (Fig. 4), pleural ultrasound, and transthoracic echocardiography (TTE), were performed. Based on the pleural findings, the patient underwent diagnostic thoracentesis, which removed 10 cc of fluid from each pleural cavity. Fluid analysis revealed a transudative nature, suggesting fluid overload as the underlying cause. The patient was subsequently started on Lasix (Furosemide) at a rate of 5 mg per hour. She also received chest physiotherapy and prophylactic antibiotics to prevent post-surgical infections. Fluid intake and output were monitored for three days, and daily TTE was performed to ensure appropriate cardiac function. After three days, no abnormalities were detected in the cardiorespiratory examination. To confirm anatomical integrity before discharge, the cardiologist ordered a PCTA, which revealed the results in Table 2.

Fig. 4

Pericardial effusion caused by cardiac overload after the surgery, which was managed with diuretics

Table 2 Findings of chest computed tomography angiography before and after the surgery

Conclusion and follow-up

The patient was discharged from the hospital five days after the operation. At her four- and six-month follow-up visits, she reported no new symptoms or complaints. TTEs performed at both follow-ups revealed normal findings, indicating a stable postoperative recovery.

Discussion

The study presents a patient with PAPVC, which was initially missed during evaluations conducted for her chest pain. An initial TTE was performed in the patient’s hometown; however, the anomaly was not diagnosed. After being referred by a cardiac imaging specialist for additional evaluations, supplementary tests such as TEE and PCTA revealed the diagnosis of PAPVC. Surgical management was performed due to symptomatic presentation and abnormal imaging findings. The patient’s recovery involved a minor and relatively common complication of cardiac function overload, which was managed smoothly with medications. Follow-up was uneventful and showed normal findings.

PAPVC has been diagnosed in approximately 0.4-0.7% of the normal population during autopsy evaluations. The prevalence of symptomatic patients is nearly equal to that of the lower range of this spectrum (0.41%) [9]. Therefore, it is considered a rare anomaly that cardiologists should keep in mind [10]. This case report underscores the fact that diagnosis was missed for almost two years after symptomatic diagnosis due to the limitations of TTE in diagnosing PAPVC. This structural anomaly is present in 0.5-1% of the population. This suggests that many patients live their entire lives with this anomaly without symptoms or a diagnosis [11]. Although there are various subtypes of this condition, nearly four-fifths of diagnosed cases involve anomalous pulmonary veins draining into the RA via a sinus venosus connection with an ASD. In contrast, the diagnosis of pure PAPVC without a septal defect is seen in approximately one-tenth of cases and is substantially rare [12]. The presented case demonstrated no septal defect.

The presentation of PAPVC is considerably nonspecific and depends on the magnitude of the intracardiac shunt and the anomalous drainage of the PV. Therefore, diagnosis is not straightforward and requires a thorough evaluation using multimodal imaging [13]. However, regardless of the type of PAPVC, it causes left-to-right shunts in pre-tricuspid level, which result in recirculation of the oxygenated blood into the pulmonary circulation, increased pulmonary blood flow, and increased volume load on the right heart. Consequently, right atrial enlargement (RAE) and right ventricular enlargement (RVE) inevitably result from these functional abnormalities [14]. In summary, it is important to note that aging and its associated effects, such as HTN and diastolic dysfunction, contribute to increased pressure in the LA compared to the RA. This, in turn, can lead to increased blood flow to the right heart and a greater left-to-right shunt. However, the amount of blood that enters the right heart is influenced by the number of abnormal connections present. For instance, it has been observed that a single anomalous pulmonary vein connection may not cause significant overload on the right side of the heart.

Additionally, an atrial septal defect can facilitate diagnosis, as imaging techniques make it more easily visualized. This condition may also be associated with greater blood shunting and an increased likelihood of developing symptoms [14]. Cyanosis is an uncommon manifestation of this condition, occurring when pressure on the right side of the heart exceeds that on the left. This pressure difference can reverse blood flow, resulting in the development of Eisenmenger’s syndrome. While PHTN is an indication for the surgical or interventional correction of PAPVC, surgery is contraindicated in cases of Eisenmenger’s syndrome, as it may worsen the patient’s condition. Standard medications are used to manage pulmonary hypertension (PHTN) [1516].

Diagnostic procedures when encountering CHD usually start with CXR and an echocardiogram. Although increased heart size, abnormally located pulmonary vessel structure, and interstitial changes in the lungs might suggest abnormalities in the cardiovascular system, the first choice for detecting anatomical heart defects is an echocardiogram. TTE and TEE are used, with TEE offering more sensitivity and specificity, especially for visualization of the entire atrial septum and PV connections [10]. A limitation of TEE is its requirement for sedation, which entails specific requirements and potential risks [14]. Overall, TEE and TTE are suboptimal for diagnosing PAPVC, and multidetector computed tomography (MDCT) or magnetic resonance imaging (MRI) angiography provides significantly higher accuracy. Newer-generation three-dimensional MDCT has proven to be an excellent diagnostic modality [14].

The management of PAPVC depends on clinical findings, hemodynamic characteristics, and anatomical features. Therapeutic options include (1) follow-up, (2) medical management, (3) surgical treatment, and (4) transcatheter interventional procedures [17]. Corrective intervention is indicated in the following situations: the presence of significant symptoms related to this anomaly, a significant left-to-right shunt indicated by a Qp/Qs ratio greater than 2, or imaging evidence showing right ventricular (RV) dilation or RV volume overload (evidenced by a D-shaped septum during diastole). Additionally, surgical repair may be necessary alongside the simultaneous correction of other serious heart lesions and in cases of frequent respiratory infections. Other indications for intervention include persistent pulmonary hypertension (PHTN) and recurrent paradoxical emboli [18]. Open surgical correction remains the gold standard treatment for these patients. However, selected patients undergoing percutaneous transcatheter modification have demonstrated excellent outcomes. The selection is based on age, anatomical features, available expertise or devices, and clinical conditions [19]. Similar cases from the literature are summarized in Table 3 for reference. A graphical abstract illustrating and summarizing different aspects of this pathology is included in this manuscript (Fig. 5).

Clinical key message (conclusion)

Although rare, PAPVC can be a potentially debilitating anomaly if it is not diagnosed on time. The presentation is nonspecific, and accurate diagnosis primarily relies on multimodal imaging techniques, especially PCTA or PMRA. Many of these patients are misdiagnosed or experience delayed diagnosis, resulting in complications and long-term impairments in cardiac function, such as congestive heart failure. Therapeutic options are determined by clinical presentation, anatomical characteristics, and the severity of the shunt. Surgical management, if indicated, is the gold standard. However, new percutaneous intervention techniques have been applied successfully and are increasingly favored for selected patients.

Fig. 5

Graphical abstract of Partial Anomalous Pulmonary Venous Connection (PAPVC)

Table 3 Presentation of a patient with partial anomalous pulmonary venous connections and their natural history