Patient handout

Low-flow low-gradient severe aortic stenosis (classical + paradoxical)

PRODUCTION

1. Your condition

This handout is for low-flow low-gradient severe aortic stenosis (classical + paradoxical). Your care team identified this based on: echo: ava ≤1.0 cm² with mean gradient <40 mmhg / vmax <4 m/s (discordant).

Other reasons your team may use this plan: echo: stroke volume index <35 ml/m² (low-flow state); exertional dyspnea / syncope / angina with discordant as; hfref with concomitant aortic stenosis (classical lflg query).

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

Medication	Starting dose	How	When	What it does
dobutamine stress echocardiography (classical LFLG)	—	—	—	DSE distinguishes true-severe (AVA ≤1.0 persists, gradient >40 with flow) from pseudo-severe (AVA opens >1.0) and assesses contractile reserve (2020 ACC/AHA VHD)
CT aortic-valve calcium score (Agatston, sex-specific)	—	—	—	Sex-specific thresholds (men ≥2000 AU, women ≥1200–1300 AU) adjudicate severity flow-independently (2020 ACC/AHA VHD)
ATTR amyloid screen (99mTc-PYP + serum/urine free light chains)	—	—	—	Paradoxical LFLG with restrictive small LV — exclude ATTR-CM phenocopy/overlap (changes prognosis + adds tafamidis pathway)

Plan: LFLG AS — adjudicate true-vs-pseudo then AVR decision (2020 ACC/AHA VHD)

3. When to call your provider

Contact your care team if any of the following happen:

True-severe symptomatic LFLG → AVR referral now — 2020 ACC/AHA VHD
Decompensation/low-output → ED + acute HF pathway; expedite AVR — 2020 ACC/AHA VHD
PYP-positive ATTR → route cardio ATTR-CM engine — amyloid pathway

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

Classical LFLG (heart pumping strength (LVEF) <50%) true-severe on DSE (AVA ≤1.0 persists, gradient >40 with flow) — Class I AVR even without contractile reserve — 2020 ACC/AHA VHD
Classical LFLG without contractile reserve on DSE — highest surgical risk; TAVR-leaning; CT calcium adjudicates severity — 2020 ACC/AHA VHD
Small restrictive LV + low ECG voltage + carpal tunnel/neuropathy in paradoxical LFLG — screen ATTR (PYP + SFLC); ATTR-AS overlap changes prognosis + adds tafamidis — amyloid phenocopy
Decompensated low-output state in classical LFLG — cautious stabilisation; AVR (often TAVR) may be definitive therapy — 2020 ACC/AHA VHD(life-threatening)

5. Follow-up

Post-AVR surveillance; route to ATTR-CM engine if amyloid confirmed; HFrEF engine for classical component

6. Sources

Guideline: 2020 ACC/AHA VHD Guideline + 2021 ESC/EACTS VHD Guideline