06 Jul 60/60 Sign Clinching The Pulmonary Embolism.
Mohamad Azzlee Mustafa, Mohd Boniami Yazid, Mohammad Zikri Ahmad, Shaik Farid Abdull Wahab, Mohd Hashairi Fauzi, Abdullah Lutfi Ismail
This case illustrates a diagnosis of pulmonary embolism (PE) by using 60/60 sign of Doppler transthoracic echocardiography (TTE).
A 33-year-old lady presented with a month history of bilateral leg swelling associated with exertional dyspnea and intermittent palpitation.
Examination revealed a non-obese patient with regular heart rate of 118 beats per minute, blood pressure of 123/87mmHg and saturation of 97% on 3L/min nasal cannula. Arterial blood gas analysis was hypoxemic with an elevated alveolo-arterial oxygen gradient (A-a O₂ gradient).
She was noted to have distended jugular neck vein, fine bibasal lungs crepitation and non-tender pitting edema in both lower limbs. The remainder of physical examination findings were unremarkable.
Bedside TTE demonstrated a D-shaped left ventricle (LV) on parasternal short axis and presence of McConnell Sign. Right ventricle (RV) was dilated with RV:LV ratio more than one and inferior vena cava (IVC) diameter was distended.
She had a measured right ventricular systolic pressure (RVSP) of 56mmHg and a pulmonary acceleration time (PAT) of 47milisec which were positive of 60/60 sign.
Two-point compression ultrasonography was negative for deep vein thrombosis. Subsequently, CT pulmonary angiography (CTPA) was done confirming presence of an embolus over left basilar pulmonary artery.
Patients of PE display wide variability of clinical presentation and therefore set physician up to possibly miss the diagnosis. Presence of RV pressure overload features on TTE (basal RV diastolic dimension of >30mm or RV:LV >1, right sided cardiac thrombus, systolic flattening of IVS and PAT <90ms or tricuspid regurgitation pressure gradient >30mmHg in absence of RV hypertrophy) yields poor specificity of PE especially in known cardiorespiratory disease.
Whereas, findings of depressed contractility of RV free wall sparing its apex (McConnell sign) and disturbed RV ejection pattern with RVSP less than 60mmHg and PAT less than 60milisec (60/60 sign) were reported with significant specificity for PE.
Combination of these positive findings should raise level of clinical suspicion of PE especially when CTPA is not urgently available.
As diagnosis of PE is not always straightforward and notoriously inaccurate based on clinical signs alone, bedside TTE served as invaluable tool when diagnosis of PE is in doubt.
References Ultrasound System HS40, Samsung Healthcare Global by using phased array transducer, PN2-4