Cardiac Hypertrophy

Question 1

Definition of Cardiac Hypertrophy?

Answer 1

“Cardiac hypertrophy is an adaptive response to pressure, volume stress or mutations”

“At the cellular level, cardiomyocyte hypertrophy is characterised by an increase in cell size”

This leads to an increase in thickness of the
myocardium.

Question 2

Pathophysiology of Cardiac Hypertrophy?

Answer 2

Hypertrophy is a compensatory mechanism:

1. Increase in afterload will lead to concentric hypertrophy (reduced filling)
2. Increase in preload will lead to eccentric
   hypertrophy (dilation)

This results in an impairment, leading to reduced
cardiac output, and eventually cardiac failure.

Question 3

Causes of right atrial Hypertrophy?

Answer 3

• Chronic Lung Disease

-Tricuspid Stenosis

-Congenital Heart Disease (E.g. Pulmonary
Stenosis)

-Primary Pulmonary Hypertension

Question 4

ECG features of Right Atrial enlargement?

Answer 4

• Peaked P wave. AKA; P Pulmonale

this will look pointy. To qualify as right atrial enlargement:

P wave must be peaked;

➢ 2.5mm in the Inferior Leads (2, 3,
aVF)
➢ 1.5mm in V1/V2

Question 5

Causes of Left Atrial Enlargement?

Answer 5

• Mitral Stenosis
• Aortic Stenosis

-Systemic Hypertension

-Hypertrophic Cardiomyopathy

Question 6

ECG features of Left Atrial Enlargement?

Answer 6

Broad, bifid (m shaped) P wave in lead 2

1. Bifid P Wave with >40ms between 2 peaks
2. Total P Wave duration > 110ms /
   Enlarged negative portion of P wave in V1
3. Biphasic P Wave with terminal negative
   portion >40ms duration
4. Biphasic P Wave with terminal negative
   portion of >1mm deep

Question 7

Causes of Right Ventricular Hypertrophy?

Answer 7

1. Pulmonary Hypertension
2. Mitral Stenosis
3. Pulmonary Embolism
4. Chronic Lung Disease
5. Congenital Heart Disease (e.g.
   Pulmonary Stenosis)
6. Arrhythmogenic Right Ventricular
   Cardiomyopathy

Question 8

ECG criteria for right ventricular Hypertrophy?

Answer 8

• Right Axis Deviation of 110° or more.
• Dominant R wave in V1 (> 7mm tall or R/S ratio > 1).
• Dominant S wave in V5 or V6 (> 7mm deep or R/S ratio < 1)

-QRS duration < 120ms (i.e.changes not due to RBBB).

Question 9

Causes of Left Ventricular Hypertrophy?

Answer 9

1. Hypertension
2. Aortic Stenosis
3. Aortic Regurgitation
4. Mitral Regurgitation
5. Coarctation of the Aorta
6. Hypertrophic Cardiomyopathy

Question 10

ECG Criteria for Left Ventricular Hypertrophy?

Answer 10

Voltage vs Non-Voltage Criteria:

Voltage:

S Wave in V1 + R wave in V5 or V6 (in mm)
= > 35mm

Non-Voltage:

Increased R Wave Peak Time > 50ms
In Lead V5 or V6
Left Ventricular Strain Pattern = ST
segment depression and T wave inversion
in left sided chest leads (V5 or V6)