Role of echo/doppler in the diagnosis of pulmonary embolism

Abstract

Summary: Echocardiography supplemented with pulsed and continuous wave Doppler facilities is a potent diagnostic tool in many cardiovascular disorders. Its potential role in the management of patients with suspected pulmonary embolism, though less extensively studied, deserves attention. Benefits of echoDoppler in these patients are as follows:(1) Echo/Doppler is a noninvasive, relatively inexpensive technique, readily available and repeatable in critically ill patients at the bedside.(2) EchdDoppler provides a number of independent parameters related to the pulmonary hemodynamics. These parameters include: (a) characteristics of blood flow velocity curves across the right heart valves as well as systolic and diastolic time intervals of the right ventricle (b) motion pattern of the interventricular septum (c) dimensions of the heart chambers and inferior (d) thickness of the right ventricular free wall (3) Echocardiography allows detection of thrombi within right heart chambers or in major branches of the pulmonary artery in some patients.(4) EchdDoppler may disclose alternative abnormalities explaining symptoms found in a patient with suspected pulmonary embolism such as pericardjal disease, myocardial infarction, aortic dissection, hypovolemic shock, etc. Echocardiographic Changes in Acute Pulmonary Embolism Acute Right Ventricular Pressure OverloadThe main role of echocardiography in patients with suspected pulmonary embolism is to disclose signs of acute right ventricular (RV) pressure overload andor failure. Pulmonary embolism will result in such hemodynamic changes when at least 3 0 4 0 % of the pulmonary arterial bed is obliterated.'T2 Therefore, claims of high sensitivity of echocardiographic diagnosis of pulmonary embolism are not realistic. Nevertheless, Kasper et aL3 found important echocardiographic changes in the majority of 105 consecutive patients with pulmonary embolism confirmed by angiography (n = 48), autopsy (n = 6), or high-probability lung perfusion scan (n= 51). Echocardiographic findings consisted of enlarged right ventricle (defined as RVEDD > 27 mm) in 75% of patients, reduced left ventricular diastolic dimension (LVEDD < 36mm) in 42%, decreased EF slope of the mitral valve ( 4 0 m d s ) in 50%, and dilated right pulmonary artery (>1 l .4 mm/m2) in 77%. Abnormal septal motion was observed in 44% of patients. All the above parameters were within the normal range in only 19 of 105 (18%) patients. However, no comparison with a control group was made. The authors developed a score used to establish an echocardiographic severity index of pulmonary embolism based on the five echocardiographic signs listed above, which scored 1 when at the upper limits of normal and 2 when abnormal. A significant correlation was found when this echocardiographic score was compared with the angiographic severity index of embolic obstruction according to Walsh et al.4 (n = 36, r = 0.72, p<O.OOI). Similar correlation was reported recently between Miller's index of angiographic obstruction5 and the ratio between ...

Proximal pulmonary emboli modify right ventricular ejection pattern

“…Coexistence of short acceleration time (tacc) and midsystolic deceleration (tmsd; which has a "notched" pattern) is considered diagnostic of severe pulmonary hypertension [5]. However, such patterns have also been observed in the setting of acute pulmonary embolism [11] and similar changes have been induced experimentally by proximal constriction of the proximal pulmonary arteries in dogs [12]. In both these situations, marked SFVC changes were found in the presence of acute but relatively mild elevation of Ppa limited by the performance of nonhypertrophied RV.…”

Massive Pulmonary Embolism with Mobile Right Atrial Thrombus in a Pregnant Patient Using Valproic Acid

“…Pregnany is among the risk factors and the risk of deep venous thrombosis and pulmonary emboli is increased four to six times due to the procoagulant state of pregnancy (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Treatment strategies of massive pulmonary embolism include thrombolysis and surgical/interventional embolectomy.…”

“…Pulmonary embolism is a life threatening condition (1)(2)(3)(4)(5)(6). Pregnancy is among the risk factors for pulmonary embolism (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14).…”

Diagnostic dilemma: Rare case of recurrent d-lactic acidosis leading to recurrent acute cardiac failure

“…In a hemodynamically unstable patient in a critical care unit, the use of bedside echocardiography is the most convenient mode of diagnosing major PE. 10 In heart failure due to PE, a major strain occurs in the right heart leading to a decrease in preload to the left heart, thus causing circulatory failure. 8 The absence of involvement of the right ventricle and isolated severe left ventricular dysfunction were against the possibility of PE leading to the collapse.…”