PART 5 ELECTRODIAGNOSTIC TESTING 5.1 Electrocardiographic findings Note: Changes in ECG measurements are relatively insensitive indicators of chamber size. 5.1.1 Alterations in P wave Tall P wave (P pulmonale) Right atrial enlargement, e.g. Chronic respiratory disease* Dilated cardiomyopathy* Tricuspid regurgitation* Wide P wave (P mitrale) Left atrial enlargement*, e.g. Dilated cardiomyopathy* Mitral regurgitation* Variable height of P wave (wandering pacemaker) Increased vagal tone* Absent P wave Atrial fibrillation* Acute atrial stretch Volume overload Atrial pathology Excessive vagal stimulation Large atria* Persistent atrial standstill Artefact Atrial pathology Hyperkalaemia Sinus arrest/sino-atrial block Normal in brachycephalics Drugs, e.g. Beta blockers Calcium channel blockers Digitalis glycosides Atrial disease, e.g. Cardiomyopathy* Dilatation* Fibrosis Hypertrophy Necrosis Electrolyte imbalances* Increased vagal tone Chronic respiratory disease* Gastrointestinal disease* Sick sinus syndrome Stenosis of bundle of His 5.1.2 Alterations in QRS complex Tall R waves Left ventricular enlargement, e.g. Cardiomyopathy* Hyperthyroidism* (C) Mitral regurgitation* Small R waves Acute haemorrhage Pericardial effusion Wide QRS Supraventricular Left bundle branch block Cardiomyopathy* Subaortic stenosis* Drugs/toxins, e.g. Doxorubicin Tricyclic antidepressants Right bundle branch block Occasionally seen in normal animals Cardiac neoplasia Heartworm disease Inherited Post cardiac arrest Ventricular septal defect Left ventricular hypertrophy* Microscopic intramural myocardial infarction Quinidine toxicity Severe ischaemia Ventricular Accelerated idioventricular rhythm* Ventricular ectopy* Ventricular escape complexes Ventricular premature complexes* Ventricular tachycardia* Deep S waves Right ventricular enlargement, e.g. Pulmonary hypertension Pulmonic stenosis Reverse-shunting patent ductus arteriosus Tricuspid regurgitation Electrical alternans Pericardial effusion Slurred upstroke Ventricular pre-excitation/Wolff–Parkinson–White syndrome Acquired heart defects, e.g. Feline hypertrophic cardiomyopathy Congenital Idiopathic 5.1.3 Alterations in P–R relationship Prolonged P–R interval (first-degree atrioventricular block) Occasionally seen in normal animals* Age-related degeneration of atrioventricular conduction system Drugs/toxins Beta blockers Calcium channel blockers Cardiac glycosides Quinidine Tricyclic antidepressants Vitamin D rodenticides Feline dilated cardiomyopathy (C) Heart disease* Hyperkalaemia q.v. Hypokalaemia* q.v. Increased vagal tone* Short P–R interval Ventricular pre-excitation/Wolff–Parkinson–White syndrome Acquired heart defects, e.g. Feline hypertrophic cardiomyopathy Congenital Idiopathic Intermittent failure of atrioventricular conduction (second-degree atrioventricular block) May be seen in normal animals Juvenile puppies at rest Physiological when seen associated with supraventricular tachycardia Drugs, e.g. Alpha-2 agonists Atropine Beta blockers Calcium channel blockers Cardiac glycosides Electrolyte imbalances* q.v., e.g. Hyperkalaemia q.v. Hyperthyroidism* (C) Increased vagal tone, e.g. Chronic respiratory disease* q.v. Gastrointestinal disease* q.v. Microscopic idiopathic fibrosis Myocardial diseases Stenosis of bundle of His Complete atrioventricular block (third-degree atrioventricular block) Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: 2: PHYSICAL SIGNS 3: RADIOGRAPHIC AND ULTRASONOGRAPHIC SIGNS 4: LABORATORY FINDINGS 1: HISTORICAL SIGNS Stay updated, free articles. Join our Telegram channel Join Tags: Differential Diagnosis in Small Animal Medicine Sep 3, 2017 | Posted by admin in SMALL ANIMAL | Comments Off on 5: ELECTRODIAGNOSTIC TESTING Full access? Get Clinical Tree
PART 5 ELECTRODIAGNOSTIC TESTING 5.1 Electrocardiographic findings Note: Changes in ECG measurements are relatively insensitive indicators of chamber size. 5.1.1 Alterations in P wave Tall P wave (P pulmonale) Right atrial enlargement, e.g. Chronic respiratory disease* Dilated cardiomyopathy* Tricuspid regurgitation* Wide P wave (P mitrale) Left atrial enlargement*, e.g. Dilated cardiomyopathy* Mitral regurgitation* Variable height of P wave (wandering pacemaker) Increased vagal tone* Absent P wave Atrial fibrillation* Acute atrial stretch Volume overload Atrial pathology Excessive vagal stimulation Large atria* Persistent atrial standstill Artefact Atrial pathology Hyperkalaemia Sinus arrest/sino-atrial block Normal in brachycephalics Drugs, e.g. Beta blockers Calcium channel blockers Digitalis glycosides Atrial disease, e.g. Cardiomyopathy* Dilatation* Fibrosis Hypertrophy Necrosis Electrolyte imbalances* Increased vagal tone Chronic respiratory disease* Gastrointestinal disease* Sick sinus syndrome Stenosis of bundle of His 5.1.2 Alterations in QRS complex Tall R waves Left ventricular enlargement, e.g. Cardiomyopathy* Hyperthyroidism* (C) Mitral regurgitation* Small R waves Acute haemorrhage Pericardial effusion Wide QRS Supraventricular Left bundle branch block Cardiomyopathy* Subaortic stenosis* Drugs/toxins, e.g. Doxorubicin Tricyclic antidepressants Right bundle branch block Occasionally seen in normal animals Cardiac neoplasia Heartworm disease Inherited Post cardiac arrest Ventricular septal defect Left ventricular hypertrophy* Microscopic intramural myocardial infarction Quinidine toxicity Severe ischaemia Ventricular Accelerated idioventricular rhythm* Ventricular ectopy* Ventricular escape complexes Ventricular premature complexes* Ventricular tachycardia* Deep S waves Right ventricular enlargement, e.g. Pulmonary hypertension Pulmonic stenosis Reverse-shunting patent ductus arteriosus Tricuspid regurgitation Electrical alternans Pericardial effusion Slurred upstroke Ventricular pre-excitation/Wolff–Parkinson–White syndrome Acquired heart defects, e.g. Feline hypertrophic cardiomyopathy Congenital Idiopathic 5.1.3 Alterations in P–R relationship Prolonged P–R interval (first-degree atrioventricular block) Occasionally seen in normal animals* Age-related degeneration of atrioventricular conduction system Drugs/toxins Beta blockers Calcium channel blockers Cardiac glycosides Quinidine Tricyclic antidepressants Vitamin D rodenticides Feline dilated cardiomyopathy (C) Heart disease* Hyperkalaemia q.v. Hypokalaemia* q.v. Increased vagal tone* Short P–R interval Ventricular pre-excitation/Wolff–Parkinson–White syndrome Acquired heart defects, e.g. Feline hypertrophic cardiomyopathy Congenital Idiopathic Intermittent failure of atrioventricular conduction (second-degree atrioventricular block) May be seen in normal animals Juvenile puppies at rest Physiological when seen associated with supraventricular tachycardia Drugs, e.g. Alpha-2 agonists Atropine Beta blockers Calcium channel blockers Cardiac glycosides Electrolyte imbalances* q.v., e.g. Hyperkalaemia q.v. Hyperthyroidism* (C) Increased vagal tone, e.g. Chronic respiratory disease* q.v. Gastrointestinal disease* q.v. Microscopic idiopathic fibrosis Myocardial diseases Stenosis of bundle of His Complete atrioventricular block (third-degree atrioventricular block) Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: 2: PHYSICAL SIGNS 3: RADIOGRAPHIC AND ULTRASONOGRAPHIC SIGNS 4: LABORATORY FINDINGS 1: HISTORICAL SIGNS Stay updated, free articles. Join our Telegram channel Join
