Identify risk factors for developing chronic thromboembolic pulmonary hypertension after acute pulmonary embolism.

Determine echocardiographic predictors of chronic thromboembolic pulmonary hypertension.

Determine the radiological predictors of chronic thromboembolic pulmonary hypertension in CT pulmonary angiography.

Chronic thromboembolic pulmonary hypertension(CTEPH) is considered to be a long-term complication after acute pulmonary embolism (PE) characterized by persistent perfusion defects of pulmonary arteries caused by fibrotic remodeling. Its pathophysiology has not been fully elucidated yet, although it has been accepted that the increased pulmonary vascular resistance is caused by obstruction of pulmonary arterial vessels by organized thromboemboli and by vascular remodeling of small un obstructed vessels. (1) Although CTEPH had been thought to develop in relatively few patients post-pulmonary thromboembolism, the latest data suggest an unexpectedly high incidence of approximately 4%. (2) In addition, although there are well-defined risk factors for pulmonary thromboembolism, the risk factors for CTEPH have not yet been sufficiently defined. (3) For that reason, the determination of risk factors is of great importance for the early diagnosis of patients with CTEPH, with its high mortality and morbidity. The clinical presentation of CTEPH is characterized by non-specific symptoms and include exercise intolerance, dyspnea, fatigue, chest pain, and syncope (at exercise). These symptoms are also consistent with other more common cardiopulmonary conditions such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease, coronary artery disease, cardiac arrhythmia or heart failure not caused by chronic pulmonary thrombi. (4) These non-specific symptoms are commonly reported by patients who suffered from an acute PE and therefore, the possibility of CTEPH can be frequently considered . The diagnostic management of CTEPH is complex. In many patients pulmonary perfusion scintigraphy, transthoracic echocardiography and conventional pulmonary angiography with determination of pulmonary hemodynamics need to be performed before the diagnosis of CTEPH can be refuted. (5)

Inclusion Criteria:

All adult patients of both gender more than 18 yrs admitted at chest department and diagnosed by CT pulmonary angiography as acute pulmonary embolism during a period of one year will be recruited in the study.

About 80 patients as the average number of patients admitted per month is 7.

Exclusion Criteria:

Patients with congenital or acquired heart diseases. Patients with chronic chest diseases. Patients previously diagnosed chronic thromboembolic pulmonary hypertension by V/Q scan.

All adult patients of both gender more than 18 yrs admitted at chest department and diagnosed by CT pulmonary angiography as acute pulmonary embolism during a period of one year will be recruited in the study.