D2I2.
cardiovascular

Arrhythmia (atrial fibrillation)

is an abnormal heart rhythm () characterized by rapid and irregular beating of the atrial chambers of the heart. It often begins as short periods of abnormal beating, which become longer or continuous over time. It may also start as other forms of arrhythmia, such as atrial flutter, that transform into AF.

Underlined words are explained — tap any of them.

Symptoms — what it feels like

  • ·None, heart , fainting, dizziness, decreased level or total loss of consciousness, shortness of breath

Treatment

  • ·Lifestyle modifications, rate control, rhythm control, anticoagulation

Complications

  • ·Heart failure, ,

The sections below are general education drawn from public guidelines (NHS, Mayo, CPIC, WHO, ICMR). They are not individually reviewed by a clinician and are not medical advice — always talk to a doctor about your own health.

For clinicians · pharmacogenomics

Genes that change how certain drugs work — and that differ in South Asians. This is education, not a dosing tool; genotype-guided prescribing is a clinician decision.

CYP2C9 + VKORC1Warfarin
CPIC A

is famously hard to dose - too little and form, too much and you bleed. Two genes largely decide how much each person needs: one controls how fast you break the drug down, the other how strongly it works. Knowing them helps a doctor get closer to the right dose sooner.

South Asian signal: CYP2C9 and VKORC1 variants together explain up to ~18% and ~30% of warfarin-dose variance respectively in Europeans, but explain proportionally less in Asian ancestry, so ancestry-specific algorithms matter. CYP2C9 and VKORC1 variant frequencies differ across Indian sub-populations; CPIC therefore provides continental-ancestry-specific dosing guidance rather than a single formula (CPIC 2017 update).

Prescriber note: Where CYP2C9/VKORC1 genotype is available, use an ancestry-appropriate validated algorithm (e.g. the CPIC-endorsed approach) for the initial dose and then titrate to INR; do not apply European-derived dose predictions unmodified to South Asian patients. CPIC recommends using a validated pharmacogenetic dosing algorithm that incorporates CYP2C9 and VKORC1 (and, for some ancestries, CYP4F2 and rs12777823) to estimate a starting warfarin dose targeting INR 2-3, rather than a fixed empirical dose, when genotype is available.

Not a dosing tool. Genotype-guided prescribing is a clinician decision; genotyping access in India is limited.

Plain-language summary adapted from Wikipedia. Not medical advice.