Routine Electrocardiography in Screening for Pulmonary Embolism

Abstract

In a group of 245 patients with clinical suspicion of pulmonary embolism we analyzed the ECG for 22 signs that have been associated with this disease. Subsequently, the patients were divided into two groups: those with confirmed embolism and those in whom embolism was not confirmed. The occurrence of the ECG signs was assessed separately for the two groups. Furthermore, we related ECG features to severity of embolism as estimated at lung scan. Tachycardia and S-T depression were the commonest findings in both groups. P-R displacement, late R in aVR, S₁Q₃T₃, S slurred and T inversion in V₁-V₂ were more frequent in embolic than in nonembolic patients (p < 0.05 or less). All the abovementioned signs were more frequent at diagnosis than at recovery in embolic patients (p < 0.05 or less), whereas only tachycardia was more frequent at diagnosis than at control in nonembolic patients (p < 0.001). S-T depression and T inversion in V₁-V₂ were also associated to severity of embolism.Since some ECG signs are very frequent or specific in pulmonary embolism, this condition should always be suspected when they are found and, particularly, when previously absent in the same patients and/or not explained by other conditions

Prognostic Significance of Inverted T Waves in Patients With Acute Pulmonary Embolism

“…9 Several studies have suggested that inverted T waves are related to the severity of acute PE, 9,15,16 whereas others have not. 17,18 Our findings suggest that the number of leads with inverted T waves is related to the short-term outcome in patients with acute PE. However, the depth of inverted T waves was unrelated to outcome, consistent with the findings of previous studies.…”

“…Acute PE is associated with a number of ECG abnormalities, but has extremely diverse manifestations and is liable to be affected by factors such as the degree of hemodynamic instability and the timing of ECG recording. [9][10][11][12][13][14][15][16][17][18] Of the many ECG abnormalities associated with acute PE, inverted T waves are the most common, 9,11,14,15,17 as well as the most persistent change. 9,11 Inverted T waves occur in 17-68% of patients with acute PE.…”

“…9 We analyzed the following ECG findings previously shown to be associated with PE: (1) arrhythmias; (2) pulmonary P: P waves ≥2.5 mm in limb leads or ≥1.5 mm in lead V1; (3) right axis deviation: QRS electrical axis >90°; (4) left axis deviation: QRS electrical axis ≤-30°; (5) complete right bundle block: QRS intervals ≥0.12 s; (6) incomplete right bundle block: QRS intervals = 0.10-0.11 s; (7) S1S2S3: the presence of S waves of at least 1.5 mm amplitude in leads I, II and III; (8) S1Q3T3: the presence of S waves in lead I and Q waves in lead III, each having amplitudes of ≥1.5 mm, in association with negative T waves in lead III; (9) low voltage: greatest overall deflection of the QRS complex ≤5 mm in all limb leads; (10) right ventricular hypertrophy: the presence of R waves >5 mm or an R/S ratio of ≥1 in lead V1; (11) clockwise rotation: a shift in the transition zone (R = S) in the precordial leads to V5 or beyond; (12) ST elevation: elevation of ST segments ≥1.0 mm in any lead except lead aVR; and (13) ST depression: depression of ST segments ≥0.5 mm in any lead in the absence of complete bundle branch block or ventricular hypertrophy. [9][10][11][12][13][14][15][16][17][18] Echocardiographic Evaluation Right ventricular function was assessed using transthoracic echocardiography. Right ventricular dysfunction was diagnosed if patients had any of the following findings: (1) abnormal motion of the interventricular septum; (2) dilation of the right ventricle (diastolic diameter ≥30 mm); (3) hypokinesis of the right ventricle; or (4) tricuspid valve regurgitation (jet velocity >2.5 m/s).…”

“…Various ECG findings specific for acute PE have been reported; however, the relationship between ECG findings and the severity of acute PE remains unclear. [9][10][11][12][13][14][15][16][17][18] Inverted T waves are frequently observed in lead III and precordial leads in patients with acute PE. 9,11,14,15,17 Some, 9,15,16 but not all, studies have shown that inverted T waves are related to the severity of acute PE.…”

“…9,11,14,15,17 Some, 9,15,16 but not all, studies have shown that inverted T waves are related to the severity of acute PE. 17,18 Previous studies assessing the clinical significance of inverted T waves in patients with acute PE have focused mainly on the presence or absence of this finding; however, the relationship between the extent of inverted T waves and the severity of acute PE remains unclear. To clarify the clinical significance of inverted T waves, we studied the relationship of the number of leads with inverted T waves to disease severity at presentation and inhospital outcomes in patients with acute PE.…”