Stenting to reverse left ventricular ischemia due to left main coronary artery compression in primary pulmonary hypertension

Extrinsic compression of coronary and pulmonary vasculature

Coronary artery disease from atherosclerosis induced stenosis remains the leading cause of acute coronary syndrome (ACS) and death worldwide, however extrinsic compression of coronary arteries from adjacent anatomical and pathological structures is an infrequent but important diagnosis to be aware of, especially given the nonspecific symptoms of chest pain that mimic angina in patients with pulmonary hypertension (PHT) and congenital heart disease. Non-invasive CT angiography is an invaluable diagnostic tool for detection of coronary artery compression, pulmonary artery dilatation and pulmonary vascular compression. Although established guidelines are not available for management of left main coronary artery (LMCA) compression syndrome, percutaneous coronary intervention and stent implantation remain a feasible option for the treatment, specifically for patients with a high surgical risk. Treatment of pulmonary vein or artery compression is more varied and determined by etiology. This review article is focused on detailed discussion of extrinsic compression of coronary arteries, mainly the LMCA and brief discussion on pulmonary vasculature compression by surrounding anatomical and pathological entities, with focus on pathophysiology, clinical features, complications and role of imaging in its diagnosis and management.

Optimal Tricuspid Regurgitation Velocity to Screen for Pulmonary Hypertension in Tertiary Referral Centers

BACKGROUND

A mean pulmonary artery pressure >20 mmHg now defines pulmonary hypertension. We hypothesize that echocardiographic thresholds need to be adjusted.

RESEARCH QUESTION

Should TRV thresholds to screen for PH be revised given the new hemodynamic definition?

STUDY DESIGN AND METHODS

This multicenter retrospective study included 1,608 patients that underwent both echocardiography and right heart catherization within four weeks. The discovery cohort consisted of 1,081 individuals and the validation cohort included 527. Screening criteria for pulmonary hypertension were derived using receiver operating characteristic analysis and the Youden index assuming equal cost for false positive and negative classification. A lower threshold was calculated using a predefined sensitivity: 95%.

RESULTS

In the discovery cohort, echocardiographic tricuspid regurgitation velocity had a good discrimination for pulmonary hypertension, AUC 88.4 (95% CI, 85.3-91.5). A 3.4 m/s threshold provided a 78% sensitivity, 87% specificity, and 6.13 positive likelihood ratio to detect pulmonary hypertension. 2.7 m/s had a 95% sensitivity and 0.12 negative likelihood ratio to exclude pulmonary hypertension. In the validation cohort, the discovery threshold of 2.7 m/s provided a sensitivity and negative likelihood ratio of 80% and 0.34, respectively. Right cardiac size improved detection of pulmonary hypertension in the lower tricuspid regurgitation velocity groups.

INTERPRETATION

Our data support a lower tricuspid regurgitation velocity around 2.7 m/s for screening pulmonary hypertension with a high sensitivity in tertiary referral centers. Right heart chamber measurements improve the diagnostic yield of echocardiography.

Left main coronary artery compression in pulmonary hypertension

Extrinsic compression of the left main coronary artery (LMCA) by a dilated pulmonary artery (PA) in the setting of pulmonary arterial hypertension (PAH) is an increasingly recognized disease entity. LMCA compression has been associated with angina, arrhythmia, heart failure, and sudden cardiac death in patients with PAH. Recent studies suggest that at least 6% of patients with PAH have significant LMCA compression. Screening for LMCA compression can be achieved with computed coronary tomography angiography, with a particular emphasis on assessment of PA size and any associated downward displacement and reduced takeoff angle of the LMCA. Indeed, evidence of a dilated PA (>40 mm), a reduced LMCA takeoff angle (<60°), and/or LMCA stenosis on CCTA imaging should prompt further diagnostic evaluation. Coronary angiography in conjunction with intravascular imaging has proven effective in diagnosing LMCA compression and guiding subsequent treatment. While optimal medical therapy and surgical correction remain in the clinician's arsenal, percutaneous coronary intervention has emerged as an effective treatment for LMCA compression. Given the prevalence of LMCA compression, its associated morbidity, and mortality, and the wide array of successful treatment strategies, maintaining a high degree of suspicion for this condition, and understanding the potential treatment strategies is critical.

Hybrid approach for treating patient with chronic thromboembolic pulmonary hypertension and extrinsic compression of left main coronary artery

Background ― Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare life-threatening form of pulmonary artery hypertension. CTEPH is potentially curable by performing surgical operation – pulmonary thrombendarteriectomy. Unfortunately, about 36% of patients with CTEPH are considered as inoperable because of different conditions including left main coronary artery compression syndrome (LMCS), caused by compression with delated pulmonary artery. Appropriate management of patients with CTEPH and LMCS remains unknown. Case report ― We report for the first time a case of a successful hybrid treatment of patient with CTEPH and LMCS. Due to high pulmonary vascular resistance (PVR) and LMCS (90% stenosis) the risk for pulmonary thrombendarteriectomy for patient was considered as high. The multidisciplinary team decided to start treatment with new method of treatment for patients with CTEPH – balloon pulmonary angioplasty. In 5 months 4 sessions of balloon pulmonary angioplasty were successfully performed. In a follow-up mean pulmonary artery pressure decreased from 57 to 37 mm Hg, PVR decreased from 20 to 7 WU. Coronary angiography showed no compression of left main coronary artery. The diameter of pulmonary artery decreased from 4.2 to 3.6 cm. Patient was reconsidered as operable and transferred to a surgical unit for pulmonary thrombendarteriectomy. Conclusion ― Effective balloon pulmonary angioplasty can lead to regression of left main compression syndrome in CTEPH patients. Balloon pulmonary angioplasty can be a “bridge-treatment” to pulmonary thrombendarteriectomy in patients with high operation risk.

Extrinsic compression of left main coronary artery by aneurysmal pulmonary artery in severe pulmonary hypertension: its correlates, clinical impact, and management strategies

Aims

Although left main coronary artery (LMCA) compression (Co) by pulmonary artery (PA) aneurysm (A) has been reported in some pulmonary hypertension (PH) series, clinical importance and management of this complication remain to be determined. In this single-centre prospective study, we evaluated correlates, clinical impact, and management strategies of LMCA-Co in patients with PH.

Methods and results

Our study group comprised 269 (female 166, age 52.9 ± 17.3 years) out of 498 patients with confirmed PH who underwent coronary angiography (CA) because of the PAA on echocardiography, angina or incidentally detected LMCA-Co during diagnostic evaluation with multidetector computed tomography. The LMCA-Co ≥ 50% was documented in 22 patients (8.2%) who underwent CA, and stenosis were between 70% and 90% in 14 of these. Univariate comparisons revealed that a younger age, a D-shaped septum, a higher PA systolic, diastolic, and mean pressures and pulmonary vascular resistance, a larger PA diameter, a smaller aortic diameter and pulmonary arterial hypertension associated with patent-ductus arteriosus, atrial or ventricular septal defects were significantly associated with LMCA-Co. Bare-metal stents were implanted in 12 patients and 1 patient underwent PAA and atrial septal defect surgery and another one declined LMCA stenting procedure.

Conclusion

Our study demonstrates that LMCA-Co is one of the most important and potentially lethal complications of severe PH, and alertness for this risk seems to be necessary in specific circumstances related with PAA. However, long-term benefit from stenting in this setting remains as a controversy.

Atrial septal defect causing angina

Left coronary artery compression syndrome is characterized by compression of the left main coronary artery between the aorta and an enlarged main pulmonary artery. A 39-year-old woman presented with angina with dyspnea on exertion for two years. Detailed investigations revealed an atrial septal defect, valvular lesions, and severe pulmonary hypertension with left main coronary artery compression. Patch closure of the atrial septal defect, left coronary artery bypass, and valve repair was carried out. The patient recovered well and was asymptomatic on follow-up. The optimal management of such patients is yet to be clarified.

Left main coronary artery compression by pulmonary artery aneurism in patients with long standing pulmonary arterial hypertension

This review focuses on a rare complication of pulmonary arterial hypertension (PAH), extravasation compression of the left coronary artery (LCA) dilated by the pulmonary artery. The review described clinical manifestations and methods for diagnostics of LCA compression, and advantages of the endovascular correction of this complication in patients with pulmonary hypertension. Selection of a device to be implanted during the endovascular intervention in these patients was discussed with due account for concomitant treatment with oral anticoagulants. As an illustration of the issue under discussion, a clinical case of acute coronary syndrome in a female patient from the PAH Registry of the V. A. Almazov National Medical Research Center was provided.

Severe Compression of the Left Main Coronary Artery in a Patient with Chronic Thromboembolic Pulmonary Hypertension

Extrinsic compression of the left main coronary artery (LMCA) can occur in patients with an enlarged pulmonary artery trunk secondary to severe pulmonary hypertension (PH). This phenomenon rarely occurs in PH; moreover, few reports have shown that chronic thromboembolic PH can be a triggering factor for this syndrome. Herein, we describe a patient with extrinsic compression of the LMCA with chronic thromboembolic PH who underwent pulmonary endarterectomy and coronary artery bypass grafting successfully. Intravenous ultrasonography (IVUS) was effective for detecting and assessing the compression.

Percutaneous Coronary Intervention for a Patient with Left Main Coronary Compression Syndrome

Left main coronary compression syndrome rarely occurs in patients with severe pulmonary hypertension. A 65-year-old woman with severe pulmonary hypertension due to an atrial septal defect suffered from angina on effort. Cardiac computed-tomography and coronary angiography revealed considerable stenosis of the left main coronary artery (LMA) caused by compression between the dilated main pulmonary artery trunk and the sinus of valsalva. Stenting of the LMA under intravascular ultrasound imaging was effective for the treatment of angina. We herein report the diagnosis and management of this condition with a brief literature review.

Compression of adjacent anatomical structures by pulmonary artery dilation

Pulmonary hypertension is the commonest condition leading to dilated pulmonary artery. We describe three different types of compression of adjacent anatomical structures by dilated pulmonary arteries. We included involvement of the left main coronary artery, left recurrent laryngeal nerve and tracheobronchial tree. Compression of these structures can cause major complications such as myocardial ischemia, hoarseness and major airway stenosis. We present a case for each scenario and review the literature for each of these complications, focusing on patients' characteristics and contemporary management.

S. Baptista L, de Resende MVC, Furlan V, Ribeiro EE. Left Main Ostial Compression in a Patient with Pulmonary Hypertension: Dynamic Findings by IVUS

BACKGROUND

Pulmonary artery dilatation is a common feature among patients with severe pulmonary hypertension. Left main coronary artery extrinsic compression by an enlarged pulmonary artery is a rare complication and a potential cause for chest pain and sudden cardiac death in patients with pulmonary hypertension. This situation is very rare and few reports have described it. Currently, the appropriate management of these patients remains unknown.

CASE REPORT

In the present report we describe the case of a 39-year-old woman who presented with a 2-year history of cardiac symptoms related to exercise. The patient underwent a 64-slice multidetector computed tomography (MDCT) coronary angiography, which showed left main coronary artery (LMCA) compression by a markedly enlarged pulmonary artery trunk (44 mm), without intraluminal stenosis or coronary artery calcium, as determined by the Agatston score. This compression was considered to be the cause of the cardiac symptoms. To confirm and plan the treatment, the patient underwent cardiac catheterization that confirmed the diagnosis of pulmonary hypertension and LMCA critical obstruction. Taking into account the paucity of information regarding the best management in these cases, the treatment decision was shared among a "heart team" that chose percutaneous coronary intervention with stent placement. An intra-vascular ultrasound was performed during the procedure, which showed a dynamic compression of the left main coronary artery. The intervention was successfully executed without any adverse events.

CONCLUSIONS

This case illustrates dynamic compression of the LMCA by IVUS, visually demonstrating the mechanism of the intermittent symptoms of myocardial ischemia in this kind of patient. It also shows that percutaneous stenting technique may be an appropriate treatment for this unusual situation.

Increased hypoxemia in patients with COPD and pulmonary hypertension undergoing bronchoscopy with biopsy

BACKGROUND AND OBJECTIVE

Patients with pulmonary hypertension (PH) are considered to be at risk for complications associated with flexible bronchoscopy (FB), but data concerning the degree of PH are often lacking. We investigated whether COPD patients with PH who undergo bronchoscopy are at greater risk for complications.

METHODS

This prospective study included 207 consecutive COPD patients undergoing FB. All underwent an echo-Doppler to evaluate pulmonary artery pressure on the day of the bronchoscopy procedure. Pulmonologists were blinded to the echocardiogram results.

RESULTS

A total of 167 patients (80.7%) had normal pulmonary pressure. The remaining 40 patients (19.3%) had PH: 27 (13.0%) mild, eight (3.9%) moderate, and five (2.4%) severe. Noninvasive hemodynamic parameters between groups before and after FB were similar. Two patients with normal pulmonary pressure developed supraventricular tachycardia. None developed hemodynamically significant dysrhythmia. Bleeding episodes between groups in bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) did not differ. PH patients who underwent BAL and TBB had decreased O2 saturation during the procedure compared with the non-PH group (23.5% vs 6.9%, P=0.033). No deaths were attributable to FB.

CONCLUSION

PH is common among COPD patients undergoing FB. PH patients undergoing BAL and TBB are at higher risk of decreased O2 saturation than those without PH. Further studies should assess the risk among COPD patients with moderate-to-severe PH.

Massive Pulmonary Artery Aneurysm Causing Left Main Coronary Artery Compression in the Absence of Pulmonary Hypertension

We report the case of a 62-year-old woman who presented with classic symptoms of stable angina. Cardiac images and catheterization results revealed absent pulmonary valve syndrome and compression of the left main coronary artery by a massively dilated pulmonary artery aneurysm. The patient's anginal symptoms were relieved after pulmonary arterioplasty. Others have described proximal left main coronary artery compression in the presence of a dilated and hypertensive pulmonary artery. To our knowledge, this is the first case in which a pulmonary artery aneurysm caused left main coronary insufficiency in the absence of pulmonary hypertension-a clinically important complication of congenital pulmonary valve-related pulmonary arteriopathy.

Percutaneous coronary intervention for left main compression syndrome due to severe idiopathic pulmonary arterial hypertension: one year follow-up using intravascular imaging

A 60-year-old woman presented with ST-elevation myocardial infarction due to extrinsic compression of the left main coronary artery (LMCA) caused by a dilated pulmonary artery (PA) with idiopathic pulmonary hypertension and was successfully treated with intravascular ultrasound- and optical coherence tomography-guided stenting. Continuous subcutaneous epoprostenol infusion therapy was initiated immediately after the procedure and increased aggressively. Imaging modalities were extremely useful in making the diagnosis and providing follow-up of LMCA compression syndrome in this case. Over the one-year observation period, a sufficient hemodynamic improvement was obtained, without exacerbation of the PA dilatation, resulting in the absence of compression of the LMCA.

A case of extrinsic compression of the left main coronary artery secondary to pulmonary artery dilatation

Extrinsic compression of the left main coronary artery (LMCA) secondary to pulmonary artery dilatation is a rare syndrome. Most cases of pulmonary artery hypertension but no atherosclerotic risk factors rarely undergo coronary angiography, and hence, diagnoses are seldom made and proper management is often delayed in these patients. We describe a patient that presented with pulmonary hypertension, clinical angina, and extrinsic compression of the LMCA by the pulmonary artery, who was treated successfully by percutaneous coronary intervention. Follow-up coronary angiography showed patent stent in the LMCA in the proximity of the dilated main pulmonary artery. This case reminds us that coronary angiography and percutaneous coronary intervention should be considered in pulmonary hypertension patients presenting with angina or left ventricular dysfunction.

Two rare conditions in an Eisenmenger patient: left main coronary artery compression and Ortner's syndrome due to pulmonary artery dilatation

The left-main coronary artery extrinsic compression due to enlarged pulmonary artery has been described in several case series. Ortner's syndrome is also a rare condition in some cardiovascular disorders. There have been no reports about these two rare conditions in the same patient. Hence, we report a very rare case of an Eisenmenger patient with severe pulmonary hypertension and dilated pulmonary artery which has compressed the left main coronary artery, severely narrowing it, and the left laryngeal recurrent nerve with subsequent Ortner's syndrome and brief literature review.

The WHO classification of pulmonary hypertension: A case-based imaging compendium

Pulmonary hypertension (PH) is defined as a resting mean pulmonary artery pressure greater than 25 mmHg. The World Health Organization (WHO) classifies PH into five categories. The WHO nomenclature assumes shared histology and pathophysiology within categories and implies category-specific treatment. Imaging of the heart and pulmonary vasculature is critical to assigning a patient's PH syndrome to the correct WHO category and is also important in predicting outcomes. Imaging studies often reveal that the etiology of PH in a patient reflects contributions from several categories. Overlap between Categories 2 and 3 (left heart disease and lung disease) is particularly common, reflecting shared risk factors. Correct classification of PH patients requires the combination of standard imaging (chest roentgenograms, ventilation-perfusion scans, echocardiography, and the 12-lead electrocardiogram) and advanced imaging (computed tomography, cardiac magnetic resonance imaging, and positron emission tomography). Despite the value of imaging, cardiac catheterization remains the gold standard for quantification of hemodynamics and is required before initiation of PH-specific therapy. These cases illustrate the use of imaging in classifying patients into WHO PH Categories 1-5.

Extrinsic Compression of the Left Main Coronary Artery: A Case of Atrial Septal Defect with Enlarged Pulmonary Artery

We report the case of an adult referred to our center with an initial diagnosis of stenosis of the left main coronary artery (LMCA). A preoperative investigation disclosed an atrial septal defect (ASD) with pulmonary artery hypertension. The angiographic studies confirmed the diagnosis and showed external compression of the LMCA by an enlarged pulmonary artery. Surgical closure of the ASD and tricuspid valve ring annuloplasty with coronary artery bypass surgery (left internal mammary artery to left anterior descending artery) were undertaken. Six months after the surgery, the patient is doing well.

Extrinsic compression of left main coronary artery by the pulmonary trunk secondary to pulmonary hypertension documented using 64-slice multidetector computed tomography coronary angiography

Compression of left main coronary artery (LMCA) secondary to pulmonary trunk dilatation is a newly recognized entity that has been associated with severe pulmonary hypertension. In this paper we present a case of extrinsic compression of LMCA caused by dilated pulmonary trunk secondary to pulmonary hypertension documented using 64-slice multidetector computed tomography (MDCT) coronary angiography. This case is followed by a review of the literature.

Endovascular therapy for left main compression syndrome. Case report and literature review

Extrinsic compression of the left main coronary artery (LMCA) can occur in patients with severe pulmonary hypertension and enlarged pulmonary artery trunk. It has been usually described in the setting of congenital defects such as atrial septal defect, ventricular septal defect, and, more rarely, isolated persistent ductus arteriosus. Functional and structural evaluation of such patients can currently be performed noninvasively with the use of cardiac CT scanning and/or MRI. The optimal management of symptomatic patients remains unknown. We report a case of extrinsic compression of the LMCA in a symptomatic patient with Eisenmenger syndrome who underwent unprotected LMCA stent implantation. We also performed a literature review of the reported cases concerning patients treated with LMCA stent implantation for the management of this condition.

Angina associated with left main coronary artery compression in pulmonary hypertension

Chest pain is a common complaint in patients with pulmonary arterial hypertension (PAH). Left main coronary artery (LMCA) compression by an enlarged pulmonary artery trunk (PAT) has been associated with angina, but appropriate diagnostic and treatment approaches remain poorly defined. We present two cases of angina caused by LMCA compression from an enlarged pulmonary artery, one of which also presented with new, severe left ventricular systolic dysfunction attributed to myocardial ischemia. Diagnosis of LMCA stenosis was made via coronary angiography followed by computed tomography-gated coronary angiography (CT-CA), which confirmed pulmonary artery enlargement as the source of extrinsic compression. Restoring LMCA patency with percutaneous intervention and/or aggressive treatment of pulmonary hypertension led to significant improvement in angina, cardiac function and quality of life. Given the negative impact on cardiac function, prompt diagnosis and treatment of extrinsic LMCA compression should be considered a priority.

Pulmonary hypertension: diagnosis and management

Pulmonary arterial hypertension is a progressive, symptomatic, and ultimately fatal disorder for which substantial advances in treatment have been made during the past decade. Effective management requires timely recognition and accurate diagnosis of the disorder and appropriate selection among therapeutic alternatives. Despite progress in treatment, obstacles remain that impede the achievement of optimal outcomes. The current article provides an overview of the pathobiologic mechanisms of pulmonary arterial hypertension, including genetic substrates and molecular and cellular mechanisms, and describes the clinical manifestations and classification of pulmonary arterial hypertension. The article also reviews established approaches to evaluation and treatment, with emphasis on the appropriate application of calcium channel blockers, prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase 5 inhibitors. In addition, the authors discuss unresolved issues that may complicate patient management, such as the clinical importance of mild or exercise-related pulmonary arterial hypertension, and they identify avenues by which treatment may advance in the future through the use of combination treatment, outcomes assessment, and exploration of alternative pharmacologic strategies.

Pulmonary hypertension: diagnosis and management

Pulmonary arterial hypertension is a progressive, symptomatic, and ultimately fatal disorder for which substantial advances in treatment have been made during the past decade. Effective management requires timely recognition and accurate diagnosis of the disorder and appropriate selection among therapeutic alternatives. Despite progress in treatment, obstacles remain that impede the achievement of optimal outcomes. The current article provides an overview of the pathobiologic mechanisms of pulmonary arterial hypertension, including genetic substrates and molecular and cellular mechanisms, and describes the clinical manifestations and classification of pulmonary arterial hypertension. The article also reviews established approaches to evaluation and treatment, with emphasis on the appropriate application of calcium channel blockers, prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase 5 inhibitors. In addition, the authors discuss unresolved issues that may complicate patient management, such as the clinical importance of mild or exercise-related pulmonary arterial hypertension, and they identify avenues by which treatment may advance in the future through the use of combination treatment, outcomes assessment, and exploration of alternative pharmacologic strategies.

A 2D FE model of the heart demonstrates the role of the pericardium in ventricular deformation

During pulmonary artery constriction (PAC), an experimental model of acute right ventricular (RV) pressure overload, the interventricular septum flattens and inverts. Finite element (FE) analysis has shown that the septum is subject to axial compression and bending when so deformed. This study examines the effects of acute PAC on the left ventricular (LV) free wall and the role the pericardium may play in these effects. In eight open-chest anesthetized dogs, LV, RV, aortic, and pericardial pressures were recorded under control conditions and with PAC. Model dimensions were derived from two-dimensional echocardiography minor-axis images of the heart. At control (pericardium closed), FE analysis showed that the septum was concave to the LV; stresses in the LV, RV, and septum were low; and the pericardium was subject to circumferential tension. With PAC, RV end-diastolic pressure exceeded LV pressure and the septum inverted. Compressive stresses developed circumferentially in the septum out to the RV insertion points, forming an arch-like pattern. Sharp bending occurred near the insertion points, accompanied by flattening of the LV free wall. With the pericardium open, the deformations and stresses were different. The RV became much larger, especially with PAC. With PAC, the arch-like circumferential stresses still developed in the septum, but their magnitudes were reduced, compared with the pericardium-closed case. There was no free wall inversion and flattening was less. From these FE results, the pericardium has a significant influence on the structural behavior of the septum and the LV and RV free walls. Furthermore, the deformation of the heart is dependent on whether the pericardium is open or closed.

Postoperative asystole in a vasculopathic man

We present a case of postoperative cardiac arrest caused by extrinsic occlusion of the right coronary artery by an aortic pseudoaneurysm. Extrinsic impingement upon the coronary arteries may result from several etiologies and lead to cardiac symptoms identical to those caused by intrinsic coronary disease. Extrinsic compression may be amenable to treatment with angioplasty or a combination of angioplasty and surgery.

Percutaneous coronary intervention for extrinsic coronary compression after pulmonary valve replacement

Coronary artery compression is a rare and potentially fatal complication after pulmonary valve replacement. This report describes myocardial infarction from extrinsic left main coronary artery compression after pulmonary valve replacement in a 10-y-old boy. He was successfully treated with percutaneous coronary intervention.

Likelihood of left main coronary artery compression based on pulmonary trunk diameter in patients with pulmonary hypertension

PURPOSE

In patients with pulmonary hypertension, extrinsic compression of the left main coronary artery by a dilated pulmonary trunk may cause angina, left ventricular ischemia, and sudden death. We assessed coronary artery compression in relation to pulmonary trunk diameter and other demographic, echocardiographic, hemodynamic, and scintigraphic variables.

METHODS

Thirty-six patients (aged 15 to 86 years) with pulmonary hypertension, either idiopathic or associated with congenital heart disease, were enrolled. Left main coronary artery compression was defined angiographically as > or =50% obstruction associated with downward displacement of the vessel. Pulmonary trunk and aortic diameters were measured by transthoracic echocardiography.

RESULTS

Twenty-six patients had angina, of whom 7 had left coronary artery compression. Compression was related to pulmonary trunk diameter (P = 0.002) and to the ratio of pulmonary trunk diameter to aortic diameter (P = 0.02). Compression was not seen at pulmonary artery diameters <40 mm; among 19 patients with values > or =40 mm, the rate was 37%. Similarly, compression did not occur at pulmonary trunk to aortic diameter ratios <1.21; among 27 patients with ratios > or =1.21, the rate was 26%.

CONCLUSION

In pulmonary hypertension, noninvasive measurement of pulmonary trunk diameter may be helpful in determining the likelihood of left coronary artery compression and in selecting patients for diagnostic coronary angiography.