Tell me 5 common heart disease with their ECG changes, and also give me ecg pics.

Reading File

Finding Sources

Searching Images

ECG ST elevation myocardial infarction STEMI

Searching Images

atrial fibrillation ECG electrocardiogram

Finding Sources

Searching Images

complete heart block AV block third degree ECG

Searching Images

left ventricular hypertrophy ECG voltage criteria

Searching Images

heart failure ECG changes cardiomegaly

Loading Image

I have excellent ECG images for all 5 conditions. Now I'll compile a comprehensive response.

5 Common Heart Diseases & Their ECG Changes

1. 🫀 ST-Elevation Myocardial Infarction (STEMI)

ECG Changes

Feature	Finding
ST segments	Convex (tombstone) elevation ≥1 mm in ≥2 contiguous leads
Reciprocal changes	ST depression in leads opposite the infarct zone
Hyperacute T-waves	Tall, peaked T-waves in the earliest phase
Pathological Q waves	Develop within hours–days (marker of necrosis)
QRS changes	R-wave loss / QS pattern in infarcted territory

Localisation:

Anterior (V2–V4): LAD occlusion
Inferior (II, III, aVF): RCA occlusion
Lateral (I, aVL, V5–V6): LCx occlusion

As described in Harrison's Principles of Internal Medicine 22E: "Profound ST elevation or depression in multiple leads usually indicates very severe ischemia. The division of acute myocardial infarction due to obstructive coronary artery disease into ST-segment elevation and non-ST elevation types is useful since the consistent efficacy [of reperfusion] differs."

ECG Image — Anterior STEMI

Anterior STEMI ECG showing prominent ST elevation in V2–V6 with convex tombstone morphology

12-lead ECG: Acute anterior STEMI. Prominent convex ST elevation is visible across V2–V6. Reciprocal ST depression is present in the inferior leads (II, III, aVF). The QRS complexes show evolving QS pattern in V2–V3, confirming transmural injury.

2. 🫀 Atrial Fibrillation (AF)

ECG Changes

Feature	Finding
P waves	Absent — replaced by chaotic fibrillatory (f) waves (best seen in V1, II)
Rhythm	Irregularly irregular R-R intervals (hallmark)
Ventricular rate	Variable; 100–160 bpm if uncontrolled
QRS morphology	Narrow (normal conduction), unless aberrancy or pre-excitation
Baseline	Fine undulating fibrillatory waves, not organized atrial activity

Tintinalli's Emergency Medicine states: "The ECG hallmarks of atrial fibrillation include the absence of discernible P waves and an irregularly irregular ventricular rhythm. With the chaotic atrial activity, distinct P waves are not noted; rather, either a flat baseline or fine chaotic fibrillatory waves are present."

ECG Image — Atrial Fibrillation with Rapid Ventricular Response

Atrial fibrillation ECG showing absence of P waves and irregularly irregular R-R intervals

12-lead ECG: Atrial fibrillation with rapid ventricular response. No organized P waves are visible; fine fibrillatory waves replace them. The R-R intervals are completely irregular across all leads. QRS complexes are narrow, confirming supraventricular origin.

3. 🫀 Complete (Third-Degree) AV Heart Block

ECG Changes

Feature	Finding
P waves	Present, regular, at normal atrial rate (~60–100 bpm)
QRS complexes	Present, regular, at slow escape rate (20–60 bpm)
PR interval	Completely variable — no fixed relationship between P and QRS
AV dissociation	P waves "march through" QRS complexes independently
QRS width	Narrow if junctional escape; wide (>120 ms) if ventricular escape

The Washington Manual of Medical Therapeutics classifies AV blocks into: 1st degree, 2nd degree (Mobitz I/Wenckebach and Mobitz II), and 3rd degree (complete). Complete heart block carries risk of drop attacks (Stokes-Adams attacks) and is an indication for permanent pacemaker.

ECG Image — Complete (3rd Degree) AV Block

Complete heart block ECG showing AV dissociation with independent P waves and slow escape rhythm

12-lead ECG: Complete (3rd degree) AV block. Total AV dissociation is present — P waves fire at a faster independent atrial rate while wide QRS complexes occur at a slow ventricular escape rate (~35 bpm). There is no consistent PR interval. Wide QRS indicates an infra-nodal escape focus.

4. 🫀 Left Ventricular Hypertrophy (LVH)

LVH is caused by longstanding hypertension, aortic stenosis, or hypertrophic cardiomyopathy.

ECG Changes

Feature	Finding
Sokolow-Lyon criteria	SV1 + RV5 or RV6 ≥ 35 mm
Cornell criteria	RaVL + SV3 > 28 mm (men), >20 mm (women)
R in aVL	≥ 12 mm alone suggests LVH
Strain pattern	ST depression + T-wave inversion in I, aVL, V4–V6 (lateral leads)
Left axis deviation	Common
P mitrale	Notched, broad P wave in II if LA enlargement coexists

Harrison's notes: "The sensitivities of conventional voltage criteria for left ventricular hypertrophy are low in middle-age to older adults and may be decreased further in obese persons and smokers, as well as with right bundle branch block."

ECG Image — Left Ventricular Hypertrophy with Strain

LVH ECG showing high voltage in precordial leads with lateral T-wave inversions and strain pattern

12-lead ECG: Left ventricular hypertrophy meeting Cornell voltage criteria (tall R in aVL + deep S in V3). Prominent T-wave inversions in V4–V6, I, and aVL represent the classic LVH "strain pattern," indicating secondary repolarization abnormality from severe hypertrophy.

5. 🫀 Heart Failure with Reduced Ejection Fraction (HFrEF) / Dilated Cardiomyopathy

Heart failure does not have a single pathognomonic ECG pattern, but several findings are characteristic:

ECG Changes

Feature	Finding
Left bundle branch block (LBBB)	Wide QRS >120 ms, broad notched R in I/aVL/V5–V6, deep S in V1 — seen in up to 25% of HFrEF
Poor R-wave progression	Loss of R-wave height V1→V4, suggesting anterior wall disease or dilation
Sinus tachycardia	Compensatory increase in HR
Atrial fibrillation	Common comorbid arrhythmia
QRS prolongation	Marker of dyssynchrony; target of CRT therapy if ≥150 ms
Non-specific ST-T changes	ST depression, T-wave inversions
LVH pattern	When due to hypertensive cardiomyopathy

Goldman-Cecil Medicine states: "Patients with heart failure and a reduced ejection fraction have substantial prolongation of the QRS duration on the surface electrocardiogram, which is a marker of abnormal electrical activation of the left ventricle" — the rationale for cardiac resynchronization therapy (CRT).

ECG Image — Heart Failure / Dilated Cardiomyopathy with LBBB

Heart failure ECG showing left bundle branch block with wide QRS, deep S in V1, and poor R-wave progression

Chest X-ray (A) + 12-lead ECG (B): Cardiomegaly with bilateral pulmonary congestion on CXR. The ECG shows a complete LBBB pattern — wide QRS complexes with broad notched R waves in lateral leads and deep S waves in V1. Poor R-wave progression across V1–V4 is consistent with dilated cardiomyopathy.

Quick Summary Table

#	Disease	Key ECG Finding
1	STEMI	ST elevation ≥1 mm in ≥2 contiguous leads + reciprocal depression
2	Atrial Fibrillation	No P waves + irregularly irregular RR intervals
3	Complete AV Block	AV dissociation: P waves & QRS independent, slow escape rhythm
4	Left Ventricular Hypertrophy	High voltage (Sokolow/Cornell) + lateral strain pattern
5	Heart Failure / DCM	LBBB, QRS prolongation, poor R-wave progression, ST-T changes

Sources: Harrison's Principles of Internal Medicine 22E; Tintinalli's Emergency Medicine; Goldman-Cecil Medicine; The Washington Manual of Medical Therapeutics; Guyton & Hall Textbook of Medical Physiology.

This is a shared conversation. Sign in to Orris to start your own chat.