ECGs

Below are examples of ECG diagnoses

Arrythmias

Tachyarrhythmias

regular narrow complex tachycardia without P waves or flutter waves = SVT

irregularly irregular tachycardia without P waves = atrial fibrillation with rapid ventricular response

regular narrow complex tachycardia with flutter waves (upright inferior and upright in V1): atrial flutter with 2:1 ventricular conduction

Bradycardias

regular wide complex bradycardia with AV dissociation (atrial rhythm 75, ventricular 42): sinus rhythm, 3rd degree AV block, ventricular escape rhythm

Conduction abnormalities

AV blocks

regular wide complex bradycardia with AV dissociation (atrial rhythm 75, ventricular 42): sinus rhythm, 3rd degree AV block, ventricular escape rhythm

RBBB

Goodwill, Sam. 2022. “Article Name Here.” Publication Name, January 1, 2023. Article Link.

LBBB

H: normal sinus
E: normal PR, wide QRS from slow conduction left (wide and notched R wave I/aVL/V5-6) and away from the right (wide S wave V1-3)
A: normal
R: delay (transition V5)
T: normal
S: ST/T discordant (opposite direction) and proportional to QRS

= LBBB with secondary repolarization changes

Acute cardiovascular

Acute coronary syndrome

Goodwill, Sam. 2023. “Article Name Here.” Publication Name, January 1, 2023. Article Link.

acute pulmonary embolism

Goodwill, Sam. 2022. “Article Name Here.” Publication Name, January 1, 2023. Article Link.

H: sinus tach
E: normal PR/QRS/QT
A: borderline right axis
R: normal T-wave
T: normal voltages
S: primary TWI anterior (V2) and inferior (III)

= acute RV strain

Structural heart disease

rheumatic heart disease

Depending on its severity, rheumatic heart disease can have multiple ECG changes: aortic regurgitation can result in left ventricular hypertrophy, mitral stenosis or regurgitation can result in left atrial enlargement with atrial fibrillation/flutter, and pulmonary hypertension resulting in right ventricular hypertrophy

H: normal sinus (P wave upright in II, biphasic in V1)
E: normal PR/QRS/QT
A: right axis (away from I, towards aVF)
R: reversed R wave (tall R in V1, persist S in V6)
T: normal
S: mild STD anterior and inferior

= RVH with secondary repolarization abnormalities

H: atrial flutter with 2:1 conduction
E: normal QRS
A: right axis
R: early R wave V1
T: normal voltages
S: normal

= atrial flutter with 2:1, RVH

H: atrial fibrillation with rapid ventricular response
E: normal
A: right axis
R: early R wave
T: tall left sided voltages
S: TWI discordant to QRS

= atrial fibrillation with rapid ventricular response, biventricular hypertrophy with secondary repolarization abnormalities

left ventricular hypertrophy

Left ventricular hypertrophy (LVH) produces tall voltages towards the left, with discordant and proportional ST/T change: I/aVL/V5-6 have tall R waves with ST depression/T wave inversion, and the mirror image is V1-3 have deep S waves with ST elevation and tall T waves

H: sinus rhythm with limb lead misplacement (P waves I>II and inverted in III)
E: first degree AV
A: normal
R: normal
T: tall voltages
S: ST/T discordant (opposite to QRS) and proportional

= LVH with secondary repolarization abnormalities