Question 6: Right heart strain

Question 6

A pt presents with breathlessness : Describe the ultrasound findings that would suggest right heart strain and what features would suggest the findings is either acute or chronic

ECHO findings suggestive of Right heart strain is TR velocity > 3.4m/s SPAP > 50 MmHg with or without additional echocardiographic variable suggestive of PH

Measurement of TR velocity:

1. Measure TR jet velocity using  CW Doppler. Need a good signal. Can use

• Apical 4 chamber
• PLAX (Tricuspid inflow – probe angled down from classical PLAX)
• PSAX at aortic level.

2. Add estimated RA pressure from IVC size and collapsibility

• add 0 – 5 mmHg is IVC <1.5 and collapsing < 50%
• add 5 – 10 mmHg if between 1.5 and 2.5 cm collapsing >50%
• add 10 -15 mmHg if > 2.5cm and collapsing <50%
• add 20 mmHg id > 2.5 cm and fixed

Features of RV strain :

Seen in both acute and  chronic right ventricular strain :

1. RV size increased

• Increased if > 2/3 of LV in apical 4 chamber
• Moderately increased  if the same size as LV
• Severely increased if > than LV.
• Normal RV size measured in apical 4 chamber : 4cm at base of RV

2. D shaped ventricle in PSAX

• IVS moving towards LV in systole suggests pressure overload
• IVS moving towards RV in diastole suggests volume overload

3. Reduced RV contractility

• TAPSE < 16mm measured from Apical 4 chamber view using M mode

4. Dilated pulmonary artery

5. Pulmonary regurgitation

6. Fixed and dilated IVC >2cm collapsing < 50%

ECHO features  suggestive of acute right heart strain in the situation of a large pulmonary embolus:

• 60/60 sign : PAP of < 60 mmHg  +  PAT < 60 msec +/- midsystolic notch
• +ve Mconnel’s sign in PE but  also seen in  patients with chronic pulmonary HT and with RV infarction. Poor +ve predictive value for PE but in combination with 60/60 sign better

ECHO features suggestive of chronic PAH

• PAP > 60 mmHg
• PAT  < 80 msec +/- midsystolic notch.PAT only valid if HR between 60 /min and 100/min
• Right ventricular hypertrophy –  wall > 5mm best seen in subcostal and PLAX views
• Percardial effusion in chronic pulmonary hypertension
• Pleural effusion
• Ascites

Look at previous ECHOS  and review patient past history to help assess whether right heart failure is acute or chronic

Essentially difficult to tell between acute and chronic right ventricular strain