Medicina_Decoded
Internal medicine, decoded step by step.
Clinical algorithms, exam traps and practice questions for NEET PG and INI-CET aspirants and medicine residents. Made by an MD Medicine doctor.
Start here
Approach to VPCs in the OPD
Red flags, reversible causes, burden, structural heart disease and when to ablate.
NewOpen algorithm →VPCs and ventricular bigeminy
Compensatory pause, RVOT morphology, digoxin, CAST and the pulse deficit.
FreeStart quiz →VPC recap sheet
The whole topic on one printable screen for last-minute revision.
FreeView recap →Get each new algorithm in your inbox
One email when a new algorithm, quiz or recap goes live. No spam, unsubscribe anytime.
Algorithms
Tap any box in an algorithm to open the explanation behind it.
Approach to VPCs and ventricular bigeminy
Two questions drive everything: is the heart structurally normal, and is the burden high or the patient symptomatic?
- Premature, wide QRS (≥120 ms) with bizarre morphology and no preceding premature P wave.
- ST–T discordant to the QRS. This is expected, not ischaemia.
- Usually a full compensatory pause: the RR around the VPC equals twice the sinus RR.
- Rule out a PAC with aberrancy: look for a premature P hidden in the preceding T wave.
- Syncope or presyncope, exertional symptoms, chest pain.
- Family history of sudden cardiac death at a young age.
- NSVT, multifocal VPCs, R-on-T (short coupling) or prolonged QTc on the ECG.
- Known LV dysfunction or prior MI.
IF YES
Continuous monitoring, troponin, electrolytes and echo. Treat as a possible malignant arrhythmia until proven otherwise.
- Electrolytes: hypokalaemia, hypomagnesaemia (correct Mg²⁺ or K⁺ will not hold).
- Drugs: digoxin toxicity (classically bigeminy), β-agonists, theophylline, QT-prolonging drugs, tricyclics.
- Stimulants: caffeine, energy drinks, alcohol, nicotine, cocaine.
- Systemic: thyrotoxicosis, hypoxia, anaemia, fever, acute ischaemia.
- ECG read: morphology, QTc, Q waves, Brugada pattern, epsilon waves.
- Burden: percentage of all beats that are VPCs. Above about 10% raises the risk of VPC-induced cardiomyopathy.
- Exercise test: VPCs that disappear with exercise are reassuring; those that increase with exercise or recovery need more workup.
- Cardiac MRI: if you suspect ARVC, sarcoidosis or myocarditis despite a normal echo.
- Morphology: LBBB pattern with an inferior axis suggests RVOT origin (usually benign). RBBB pattern means LV origin.
The substrate, not the VPC count, decides prognosis in a diseased heart.
IF YES
Guideline therapy for the underlying disease. Avoid class IC drugs (flecainide, encainide) after MI: in the CAST trial they increased mortality.
High burden can depress LV function even when the patient feels well, so burden alone can justify treatment.
IF NO
Explain that the beats are benign. Repeat Holter and echo at intervals if the burden is borderline, so cardiomyopathy is caught early.
Metoprolol or bisoprolol, or verapamil or diltiazem. Flecainide is an option only in a structurally normal heart.
VPC-induced cardiomyopathy often reverses after successful ablation of the focus.
Ventricular bigeminy: three bedside points
Pulse deficit
The VPC often produces no palpable pulse, so the radial pulse or SpO₂ monitor reads about half the true rate. Count from the ECG.
Think digoxin
Digoxin toxicity, especially with hypokalaemia, is the classic cause. Bidirectional VT signals severe toxicity.
Rule of bigeminy
The long pause after each VPC makes the next VPC more likely, so the pattern keeps itself going.
Suppressing asymptomatic VPCs after MI with class IC drugs increases mortality (CAST). After an MI, you treat the substrate: β-blocker, revascularisation and an ICD guided by EF.
Quizzes
Short sets with full explanations. Your best score is saved on this device.
VPCs and ventricular bigeminy
PDF notes
One-page recaps you can screenshot or print. All notes are written and drawn by Medicina Decoded.
VPCs on one screen
| Point | What to remember |
|---|---|
| ECG | Wide (≥120 ms), early, no premature P, discordant ST–T, full compensatory pause |
| vs PAC with aberrancy | Aberrancy: premature P before it, usually RBBB pattern, non-compensatory pause |
| Bigeminy | Every second beat is a VPC. Classic cause: digoxin toxicity. Pulse deficit |
| NSVT | ≥3 beats at >100/min lasting <30 seconds |
| RVOT origin | LBBB pattern + inferior axis. Commonest idiopathic, usually benign |
| Burden | >10% on Holter: watch for VPC-induced cardiomyopathy |
| Reassuring | Normal echo, low burden, VPCs vanish on exercise |
| Treatment | β-blocker or non-DHP CCB, then ablation if refractory or LVEF falls |
| Trap | CAST: class IC after MI increased mortality |
On the live site this recap will download as a PDF. Here, take a screenshot or use your browser's print option.
Videos
ECG_DECODED: one ECG, decoded in under a minute. Real ECGs, traced and animated, with the mechanism behind every wave.
ECG_DECODED episodes
Pericarditis vs STEMI
Smiles everywhere = pericarditis. Tombstone + mirror = STEMI.
Diffuse concave ST, PR depression, aVR reversed, Spodick's sign, reciprocal change, Q waves. Full 4-minute breakdown.
New · full breakdownRBBB: rabbit ears in V1
r = septum · S = left ventricle · R′ = late right ventricle.
Where the second R comes from, and why V6 gets a wide, slurred S. Mnemonic: WiLLiaM MaRRoW.
Wellens syndrome
Pain-free, troponin normal, deep T in V2–V3: never a TMT.
Critical proximal LAD stenosis: why the troponin can be normal and why a stress test is dangerous.
6 SVTs, 6 circuits
Sinus, AVNRT, AVRT, focal AT, flutter, MAT.
Where each circuit runs, with real lead II strips.
Heart rate exactly 150
Regular narrow tachycardia at 150 = flutter 2:1 until proven otherwise.
Find the hidden flutter wave, and why adenosine unmasks but doesn't cure.
AF + WPW: the verapamil trap
Irregular, broad, bizarre and fast? Avoid the A, B, C, D.
Why blocking the AV node sends every impulse down the accessory pathway.
Inferior STEMI + nitrate = BP crash
Check V4R. RV infarct: fluids, not nitrates.
III more than II, ST up in V1: the right ventricle is preload dependent.
More series
DRUGS_DECODED
Diabetes and kidney drugs, from mechanism to exam trap, based on Harrison 22e.
Open playlist →NEURO_DECODED
Neurology made simple: the rule of 4, the brainstem and localisation.
Open playlist →60-second concepts
Quick "why" questions answered in under a minute.
Follow @medicina_decoded →Exam guidance
How to use this site for NEET PG and INI-CET medicine preparation.
1. Learn the approach, not the list
Medicine questions increasingly test the next step. Read each algorithm top to bottom once, then cover the boxes and rebuild it from memory.
2. Test the same day
Do the matching quiz right after the algorithm. Read every explanation, including for the questions you got right.
3. Revise from the recap
Use one-page recaps for spaced revision: after 1 day, 1 week and 1 month. Keep the screenshots in one folder.
4. Collect the traps
Every page ends with an examiner's trap. Keep a running list; these are the points that separate close ranks.
Exam pattern, dates and marking scheme change each year. Always confirm them in the official NBEMS and AIIMS bulletins.
About Medicina Decoded
Medicina Decoded is an independent medical-education brand that decodes internal medicine and ECGs for NEET PG, INI-CET and USMLE aspirants, MBBS students and medicine residents.
What we make
Step-by-step clinical algorithms, the ECG_DECODED video series (real ECGs, traced and animated, with the mechanism behind every wave), quizzes with full explanations and one-page recaps for revision.
Who makes it
Medicina Decoded is made by a practising doctor with an MD in Internal Medicine. Content follows standard references such as Harrison's Principles of Internal Medicine and current guidelines.
Official channels
These are the only official Medicina Decoded accounts. Medicina Decoded is not affiliated with any other creator or page.
Instagram @medicina_decoded · YouTube Medicina_decoded · X @MedicinaDecoded · Telegram · Facebook
For education only, not medical advice. Contact: contact@medicinadecoded.com
Subscription confirmed
Thanks for joining Medicina Decoded. You'll get an email each time a new algorithm, quiz or one-page recap goes live.