Echo Signs of PE: McConnell's Sign and the 60/60 Rule

McConnell's sign and the 60/60 rule are used for rapid bedside assessment of the right ventricle (RV) when PE is suspected. Below are definitions, threshold values, evidence-based accuracy, and interpretation pitfalls.

McConnell's Sign

McConnell's sign is a regional pattern of RV dysfunction: akinesia or severe hypokinesia of the mid-free wall of the RV with preserved (often enhanced) contractility of its apex — known as "apical sparing." It is assessed from the apical 4-chamber view. Described by McConnell et al. in 1996 as a sign of acute RV overload.

The presumed mechanism of apical sparing is the "tethering" of the RV apex by the normally contracting apex of the left ventricle and the specific distribution of wall stress during acute afterload increase.

Accuracy. In the original study (1996), sensitivity was 77%, specificity 94%, positive predictive value 71%, and negative predictive value 96%. In later studies and meta-analyses, sensitivity was significantly lower (around 20–30%) with very high specificity (95–98%). Conclusion: the sign is specific but not sensitive — its presence makes PE likely, but its absence does not rule out the diagnosis.

The sign is not pathognomonic: a similar pattern is described in RV infarction, arrhythmogenic RV cardiomyopathy, and chronic pulmonary hypertension, thus it should be interpreted only in the clinical context.

The 60/60 Rule

The 60/60 rule (Kurzyna et al., 2002) combines two Doppler thresholds:

• acceleration time of flow in the RV outflow tract / pulmonary artery (AccT) ≤ 60 ms — pulsed-wave Doppler in the pulmonary trunk, often with a mid-systolic "notch" in the ejection curve;
• peak systolic gradient of tricuspid regurgitation (TR) ≤ 60 mm Hg

The logic of the sign: in acute PE, a previously normal thin-walled RV does not have time to hypertrophy and cannot suddenly generate high pressure — hence the TR gradient remains ≤ 60 mm Hg, and the ejection pattern is disturbed (short AccT). In chronic pulmonary hypertension, the hypertrophied RV generates a gradient > 60 mm Hg, and the rule does not apply. Thus, 60/60 helps differentiate acute overload from chronic.

Accuracy: sensitivity about 25%, specificity about 94% (Kurzyna, 2002; confirmed by subsequent studies). Like McConnell's sign, it is highly specific but not sensitive.

Summary of Echo Signs of Acute RV Overload

Limitations and Place in the Algorithm

Neither sign can be used to exclude PE due to low sensitivity. In a hemodynamically stable patient, a normal echocardiogram does not rule out the diagnosis — the reference method for verification is CT pulmonary angiography. Echocardiography is most valuable: (1) in an unstable patient with suspected high-risk PE — as a rapid bedside test for RV dysfunction, supporting the decision for reperfusion; (2) for risk stratification in confirmed PE — signs of RV dysfunction classify the patient as intermediate-high risk (ESC, 2019).

Pitfalls: pre-existing chronic pulmonary hypertension "breaks" the 60/60 rule (gradient > 60 mm Hg); unfavorable insonation angle and severe TR underestimate velocity parameters; McConnell's sign can be mimicked by RV infarction.