Findings in Cardiac and Non-cardiac Diseases

div epub:type=”chapter” role=”doc-chapter”>



© Springer Nature Singapore Pte Ltd. 2020
J. VarshneyElectrocardiography in Veterinary Medicinehttps://doi.org/10.1007/978-981-15-3699-1_11


11. Electrocardiographic Findings in Cardiac and Non-cardiac Diseases



J. P. Varshney1 


(1)
Veterinary Medicine, Shri Surat Panjarapole Prerit Nandini Veterinary Hospital, Surat, Gujarat, India

 



11.1 Electrocardiographic Findings in Cardiac Diseases









































































































































































































































































Diseases


ECG findings


Aortic stenosis


Arrhythmias

 

ECG changes are related to left ventricular hypertrophy


Subaortic stenosis


ECG may be normal

 

In severe cases “R” wave amplitude is increased (more than normal limits)

 

There is left axis deviation (MEA < 40°)

 

S-T segment may be depressed

 

“T” wave changes are also conspicuous


Pulmonic stenosis


Axis is deviated toward right (MEA > 104° on frontal plane)

 

ECG changes are related to right ventricular hypertrophy

 

(There is large S wave in leads I, II, III)

 

“S” wave is deep (in left precordial chest leads)


Mitral valve stenosis


“P” wave may be tall (>0.4 mV) and broad (>0.04 s)

 

Supraventricular premature complexes may be seen

 

Tachycardia may be conspicuous

 

Atrial fibrillation/flutter may occur

 

ECG changes related to right ventricular enlargement may be seen


Atrial septal defect


ECG may show right heart enlargement pattern


Ventricular septal defect


Biventricular enlargement pattern may be seen in ECG


Patent ductus arteriosus (left to right shunting)


ECG may show left ventricular enlargement pattern with a normal QRS axis on frontal plane

 

“R” wave voltage is increased in leads II, III, aVF, V2, and V4

 

Presence of broad “P” wave (>0.4 s) is suggestive of left atrial enlargement


Patent ductus arteriosus (with pulmonary hypertension)


ECG may show right ventricular enlargement pattern

 

There may be right axis deviation (MEA > 104°)

 

Deep “S” wave may be seen in leads I, II, and III


Chronic mitral insufficiency (CMI)


ECG may be normal or abnormal

 

“P” wave may be broad (>0.04 s), tall (>0.4 mV), and notched (lead II)

 

“R” wave amplitude is increased in lead II (more than 2.5 mV)

 

CV6LU (more than 3.0 mV), and CV5RL (more than 0.5 mV)

 

“Q” and “S” wave amplitudes are increased (more than 0.5 mV) in leads I, II, and III

 

“QRS” is broad

 

“T” wave depression may be evident

 

S-T segment abnormalities are common

 

Supraventricular premature beats may occur

 

Ventricular premature complexes may be seen

 

Atrial fibrillation may be evident

 

Paroxysmal supraventricular tachycardia may occur


Tricuspid insufficiency (TI)


Lead II may show broad “P” with/without increase in amplitude

 

P-R interval is increased (more than 0.14 s)

 

“Q” and “S” waves show increased depth in leads II, III, aVF, and CV6LU

 

“QRS” is broad (more than 0.06 s)

 

“R” wave amplitude is decreased in leads II, III, aVF, and CV6LU

 

“R” wave amplitude is increased in leads aVR and CV5RL

 

Arrhythmias are not very common


Aortic insufficiency (AI)


Changes similar to chronic mitral insufficiency (CMI)


Pulmonary valve insufficiency (PI)


Lead II may show broad “P” with/without change in amplitude

 

P-R interval is increased (more than 0.14 s)

 

“R” wave amplitude is decreased in leads II,III, aVF, and CV6LU

 

“S” wave is deep in leads II, III, aVF, and CV6LU

 

“QRS” is broad

 

Some dogs with congenital PI may show normal ECG

 

Arrhythmias are not very common


Bacterial endocarditis


ECG may be normal or abnormal

 

There may be sinus tachycardia

 

S-T segment abnormalities (elevation or depression) are common

 

“Q” wave in lead II is deep

 

ECG may show premature ventricular complexes/ventricular

 

Tachycardia or AV blocks

 

“R” wave amplitude is increased in leads II, avF, CV6LL, and CV6LU

 

“QRS” is broad

 

“P” wave duration is increased


Dilated cardiomyopathy (DCM)


Rhythm is sinus

 

“P” may be broad and tall

 

Arrhythmias (atrial fibrillation, ventricular premature complexes, ventricular tachycardia, “R”-alternans) may be present

 

“QRS” is broad

 

S-T segment may show slurring


Hypertrophic cardiomyopathy (HCM)


Atrioventricular blocks are seen

 

Bundle branch blocks may be present

 

Left atrium is enlarged (P > 0.04 s)

 

Left ventricle is hypertrophied


Secondary myocarditis


S-T may show slurring, depression, or elevation in leads II, III, aVF, V2 and V4

 

Atrioventricular (AV) block may be present

 

Bundle branch block may be present

 

Ventricular arrhythmias such as ventricular premature complexes or ventricular tachycardia may be present


Infective myocarditis


S-T segment abnormalities are common

 

Conduction disturbances are common


Pericardial effusions


“R” wave amplitude is decreased in all leads including chest leads (<1.0 mV)

 

Electrical alternans (varying amplitude of “R” wave) is commonly seen

 

Rhythm may be sinus or arrhythmic (tachycardia)


Constrictive pericarditis


Low-voltage complexes are common

 

“P” wave may be broad (more than 0.04 s)

 

Rhythm may be sinus or arrhythmic

 

Supraventricular arrhythmias may be seen


Restrictive cardio-myopathy


Atrial fibrillation may be seen

 

Ventricular arrhythmias may be seen

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Jul 17, 2021 | Posted by in INTERNAL MEDICINE | Comments Off on Findings in Cardiac and Non-cardiac Diseases

Full access? Get Clinical Tree

Get Clinical Tree app for offline access