#t wave

Electrocardiogram – ECG

Speed ​​= 25mm / sec => 1cm = 0.4 sec (x-axis)

Amplitude of 1 cm / mV => 1cm = 1mV (ordinate)

Normal values:

P wave -> 0.08 to 0.10 s; <0.25 cm

PR space -> from 0.12 to 0.20 s

QRS -> <0.08 s

ECG sinus rhythm “normal”

General: PR:

– Prolongation of the PR interval reflects the existence of an atrioventricular block

– The shortening of the PR interval reflects the existence of an accessory…

Ecg – what is the normal height of T wave?

There are two types of ecg leads,  limb leads and precordial or chest leads. 

The height of T waves are different for these two type of leads.

In limb leads- less than 5 mm. In precordial leads- less than 🔟 mm.

So if the length is more than the above mentioned values it’s probably not normal.

For various medical conditions particularly those associated with angina or infarction of the heart ♥ .

T wave is a the positive deflection after each QRS complex. It represents ventricular repolarisation.

Characteristics of a normal T wave:

Upright in all leads except aVR and V1

Amplitude <5mm in limb leads, <15mm in precordial leads

Duration

T Wave abnormalities

Hyperacute T waves

Inverted T waves

Biphasic T waves

'Camel Hump' T waves

Flattened T waves

Peaked T waves

Tall, narrow, symmetrical peaked T-waves are characteristically seen in hyperkalaemia

Hyperacute T waves

Broad, asymmetrically peaked

Seen in early stages of STEMI and often precede the appearance of ST elevation and Q waves

Also seen in Prinzmetal angina

Inverted T waves seen in the following conditions

Normal finding in children

Persistent juvenile T wave pattern

Myocardial ischemia and infarction

Bundle branch block

Ventricular hypertrophy (strain patterns)

Hypertrophic cardiomyopathy

Raised intracranial pressure

T wave inversion in lead III is a normal variant. New T wave inversion is always abnormal. Pathological T wave inversion is usually symmetrical and deep (>3mm). 

Left Bundle Branch Block

T wave inversion in the lateral leads: lead I, aVL, V5 - 6

Right Bundle Branch Block

T wave inversion in the right precordial leads V1 - 3

Ventricular Hypertrophy

Left ventricular hypertrophy produces T wave inversion in the lateral leads lead I, aVL, V5 - 6 (left ventricular 'strain' pattern) - similar to LBBB

Right ventricular hypertrophy produces T wave inversion in the right precordial leads V1 - 3 (right ventricular 'strain' pattern) and also the inferior leads (II, III, aVF)

Pulmonary Embolism

Acute right heart strain produces a similar pattern to R ventricular hypertrophy

More commonly known - the S1Q3T3 pattern (S wave in lead I, Q wave in lead III, T wave inversion in lead III)

Hypertrophic Cardiomyopathy (HOCM)

Associated with deep T wave inversions in all precordial leads

Raised Intracranial Pressure

Widespread deep T wave inversions with bizarre morphology

Biphasic T waves

Two main causes are:

Myocardial ischemia

Hypokalaemia

2 Waves go in opposite direction

Myocardial ischemia: T waves go up then down

Hypokalaemia: T waves go down then up

Ischemic t waves

Hypokalaemic t waves

Flattened T waves

Non-specific finding