A-Z NAVLE review part 2

What does the S1 heart sound signal?

Closure of AV valves and end of systole

What does the S2 hear sound signal?

Closure of semilunar valves and end of systole

When might an S3 heart sound be heard?

Increased venous return or pregnanct

What is the S4 heart sound associated with?

Atrial contraction

In what animal can the S4 heart sound be head?

Horses

What age of dogs is heart clock commonly seen at?

Middle to older dogs

What can cause increased vagal tone leading to heart block?

Drugs, endocarditis, DCM, HCM, hyperkalemia

What CS are seen with high-grade heart block?

Syncope, exerintol, and weakness

How does heart block appear on an ECG?

Decreased HR w/no QRS, large T

What are the different degrees of heart block?

1st-3rd degree

What is the long-term management for heart block?

Pacemaker

Should antiarrhythmic drugs be given for heart block, and why or why not?

Don’t give antiarrythmic drugs, may suppress rhythm

Which breeds are commonly affected by Sick Sinus Syndrome?

Female mini Schnauzers, Dachshunds, Pugs

What arrhythmias are seen with Sick Sinus Syndrome?

Supraventricular tachyarrhythmias

How does Sick Sinus Sinus appear on ECG?

Sinus bradycardia, sinus arrest, SA block

What is required for long-term treatment of sinus syndrome?

Permanent pacemakers

Do asymptomatic dogs w/abnormal ECGs indicative of Sick Sinus require treatment?

No

What are the different types of supraventicular tachycardia?

Atrial premature contractions, paroxysmal atria tachycardia, atrial flutter, and atrial fibrillation

What is the typical heart rate during supraventricular tachycardia?

>180 bpm

Is Supraventricular Tachycardia always hemodynamically sig?

Not always

How is the rhythm described in supraventricular tachycardia?

Regularly irregular rhythm

What does QRS complex look like on an ECG in supraventricular tachycardia?

Normal QRS

What is the treatment for supraventricular tachycardia to restore sinus rhythm?

Vagal maneuver to restore sinus rhythm

What types of drugs are used for chronic long term treatment of Supraventricular tachycardia?

Digoxin

Is Atrial fibrillation more common in dogs or cats?

Dogs

What conditions are associated with Atrial fibrillation?

MR, DCM, GDV, anesthesia, heatstroke, and trauma

Describe the pulse in atrial fibrillation?

Rapid irregular pulse w/chaotic rhythm

How is the rhythm described in atrial fibrillation?

Irregularly irregular

What does the ECG show in Atrial Fibrillation?

Chaotic pattern w/ no P waves

Can atrial fibrillation be cured?

No

What is the goal of treatment for atrial fibrillation?

Slow ventricular response rate so heart can fill better

What drugs are used for chronic, long-term treatment of Atrial fibrillation?

Digitoxin

What can cause ventricular premature contractions (VPCs)?

Myocarditis, DCM, lyte disorders, and trauma

Are VPCs typically hemodynamically sig.?

Rarely unless VPCs are frequent

When might VPCs cause hypotension or acid/base disturbances?

If VPCs are more frequent

How does VPC appear on an ECG?

Bizarre QRS >3 consecutive beats not preceded by P wave

How is the heart rate described when there are multiple consecutive VPCs?

>160-180 bpm

What is the goal of treatment for VPCs?

Eliminate CS and prevent sudden death

What is the emergency treatment for ventricular arrhythmias?

IV lidocaine or procainamide or O2 administration

Which animal species and demographic is commonly affected by hypertrophic cardiomyopathy (HCM)?

Middle aged male cats

What type of heart dysfunction is HCM?

Diastolic heart dysfunction

CS of HCM

• Pale mm

• Jug venous distension

• Lack of femoral pulse

• Murmur

• Rear limb paralysis

  • Pain

Is arrythmia usually seen with HCM?

No not usually

What is the definitive diagnostic method for HCM?

Echocardiogram

What is seen on an echo in HCM?

Enlarged heart at expense of lumen

What is the goal of treatment for HCM, and type of drugs are drugs are used?

• B-blockers (Atenlol)

• Ca2+ channel blocker (Dilitiazem)

• Oxygen ± aspirin

• Furosemide

• Goal: To relax and slow the heart

Is digitalis used to treat HCM and why or why not?

No digitalis is not used because the heart pump is normal

Which animal species and demographic are commonly affected by Dilated Cardiomyopathy?

Large breed dogs

Which breeds are mentioned as commonly affected by DCM?

Doberman Pinscher, GSD, Saint Bernard, Irish Wolfhounds, Cockers

Is DCM common in cats?

Rare

What type of heart dysfunction in DCM?

Systolic dysfunction

What are CS of DCM?

Coughing, wt loss, weakness, ascites, syncope

What are the PE findings in DCM?

ADR, weak femoral pulses, arrhythmias (Afib and Vtach), gallops, jugular venous distension

What is seen on rads in DCM?

Pulmonary vein and vena cava enlarged, pulmonary edema

What is seen on an echo in DCM?

Dilation of atria and ventricles

What are the goals of treatment for DCM regarding afterload and contractility?

Decreased afterload and augment contractility

What class of drug is Enalapril, and for what condition is it used?

ACE inhibitor used to treat DCM

What type of drug is Digoxin and what conditions is it used for?

Cardiac glycosides used to treat DCM

What other types of drugs are used to treat DCM?

Diuretic if congested, procainamide if Vtach

How do ACE inhibitors work?

Inhibit angiotensin I → angiotensin II and production of aldosterone

What effects do ACE inhibitors have on peripheral vasoconstriction, Na and H2O retention?

Decreased peripheral vasoconstriction and NA and H2O retention

What are ACE inhibitors classified as regarding preload and afterload?

Afterload and preload reducers

What positive effects do ACE inhibitors have?

Vasodilation and reverse remodeling

What is the common suffix for ACE inhibitor drugs?

The “-pril” drugs

How is Enalapril activated and cleared?

Prodrug activated in liver, renal clearance

How is Benazapril clear?

Hepatic clearance

What are the potential side effects of ACE inhibitors?

Renal failure (decreased GFR), hypotension

Why should ACE inhibitors not be used w/NSAIDs

Together can affect kidney function and cause acute kidney injury

What type of vasodilator is Hydralazine?

Pure arteriolar vasodilator

What effect does Hydralazine have on afterload and BP?

Potent afterload reducer and decreased BP

What conditions is Hydralazine indicated?

Chronic valve disease and DCM

Does the dose of hydralazine need to be titrated?

Yes

What are potential side effects of Hydralazine?

Hypotension and increased HR

What type of drug is Amlodipine?

Ca2+ channel blocker

What type of vasodilator is Amlodipine?

Arteriolar vasodilator

For what is Amlodipine used in cats?

Treat hypertension in cats (with or without heart disease)

When is Amlodipine in conjuction w/ an ACE inhibitor in dogs?

To further decrease afterload

What is Nitroglycerin primarily used for?

Preload reducer, venous capacitance

What effect does Nitroglycerin have on preload?

Preload reducer, venous capacitance

Is Nitroglycerin used for emergency or chronic treatment?

Emergency use for CHF, blood in shunted to capacitance vv

What type of antiarrhythmic drug is procainamide?

Membrane stabilizer

How does Procainamide affect conduction and automaticity?

Slowed conduction, less automaticity

For what type of arrythmias is IV Procainamide used for emergency treatment?

Ventricular arrythmias

What type of antiarrythmic drug is Lidocaine?

Membrane stabilizer

What type of arrythmias is lidocaine used as emergency treatment?

Ventricular arrythmias

What is the half-life of IV lidocaine and how is it administed?

Short ½ life so required slow IV drip

What class of drug is Propanolol?

Class II Beta-blocker

What effect does Propanolol have on heart rate and contractility?

Negative chronotrope and inotrope

For what conditions is Propanolol used?

Tachycardia and HCM to decrease heart and increased filling time

How does Propanolol help in conditions like Atrial tachycardia and HCM?

Decreased heart and increasing filling time

What are some potential side effects of Propanolol?

Bronchoconstriction, bradyarrythmias, hypotension, heart failure, hypoglycemia

What calls of drug is Atenolol?

Class II B blocker, specific to B1

What makes Atenolol different from Propanolol in terms of side effects?

Don’t see bronchiolar effects

What type of drug is Ditiazem?

Ca2+ channel blocker

For what coditions is Diltiazem used?

Atrial tachycardia and HCM

What type of drug is Digoxin?

Cardiac glycoside

What effect does Digoxin have on contractility and heart rate?

Positive inotrope, negative chronotrope

For what condition is Digoxin used?

Supraventricular tachycardia, CHF, DHF

What is the sig side effect of Digoxin?

Arrhythmogenicity, N, V, D via stimulation of CRTZ

How is Digoxin dosed?

On lead body weight