DrMKZ

1. Identify ASD;secundum, primum, sinus venosus ASD, coronary sinus defect
2. Assess, maximum ASD defect in multiple orientation, shape, shunt direction of the shunt- left to right, colour doppler flow
3. The rims of the ASD, – important for ASD closure device closure.
4. look for overlume overloaded, RV dilatation, RV dilatation, increase in the RV volume,
5. Estimate PASP – 4 TR max ^2 + RAP
6. PA size, RV function, TR severity, PVR
7. Calculate shunt, Qp/Qs >1.5 RHC
8. RV function, TAPSE, RV S;
9. Associated anomalies. ( PH, TR, Aortic root dilatations,

ASD → L→R shunt → RA/RV volume overload → pulmonary circulation

Another patient we did TOE.

understanding the rim of ASD

I wonder if we do 3D Echo can we even see better.

Ada 1 machine Echo yang hebat har itu maybe boleh guna untuk patient ni

Different patient, form Journal

So next we will do RHC for 1 of our patient.

So what will we know about this patient later ?

1. Oxygen saturation step-up — confirms/quantifies L→R shunt

Take saturations from:

• SVC
• IVC
• Right atrium
• RV
• PA
• Systemic arterial sample

With an ASD, you typically see an oxygen saturation step-up at the RA level because oxygenated LA blood enters the RA.

2.Qp/Qs — size of the shunt

Using Fick principle:$$Qp/Qs = \frac{SaO_2-SvO_2} {S_{PV}-S_{PA}}$$

Conceptually:

≥1.5 → generally considered a significant shunt in ASD assessment, provided the clinical context supports closure.

Qp/Qs = 1 → no significant shunt

>1 → L→R shunt

3. Pulmonary artery pressure

Measure:

• mPAP
• PASP
• PADP

This determines whether pulmonary hypertension is present.

4. Pulmonary capillary wedge pressure (PCWP)

Important because elevated PCWP suggests post-capillary pulmonary hypertension from left-heart disease rather than isolated pulmonary vascular disease.

5. Pulmonary vascular resistance — PVR$$PVR = \frac{mPAP-PCWP}{CO}$$

Units:

Wood units (WU)

Example:

mPAP = 45 mmHg
PCWP = 10 mmHg
CO = 5 L/min$$PVR=\frac{45-10}{5}=7\,WU$$

This is important because high PVR changes the safety and appropriateness of ASD closure.

6. RHC can distinguish the type of pulmonary hypertension

7. Important in ASD closure

The RHC question is essentially:

“Is this ASD causing a significant shunt, and has it produced irreversible pulmonary vascular disease?”

So before closure, particularly in an ASD patient with suspected PH, you want:

mPAP + PCWP + CO + PVR + Qp/Qs + oxygen saturation step-up.

If you give me the RHC numbers (SVC/IVC/RA/RV/PA sats, pressures, PCWP and cardiac output),

banyak lagi ni kena belajar.

ASD assement for device closure.

14.10.2026 nanti kita update balik pasal kes ni.

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Disclaimer this is a self learning note ok. Jangan saman.

Reference.

untuk baca

https://link.springer.com/article/10.1186/s43044-019-0038-7