EIM 9 Cardio

Question 1

Tricuspid Valve Regurg

Answer 1

usually physiologic, silent on auscultation in clinically normal horses​

detectable by Doppler studies in many clinically normal horses.

Question 2

What murmur grade is less likely to be clinically relevant?

Answer 2

2 or less

Question 3

If a diastolic mitral valve fluttering is identified, what other pathology needs to be ruled out? ​

Answer 3

Aortic valve regurgitation

Question 4

What is the most commonly recognized congenital heart defect in foals?

Answer 4

Perimembranous ventricular septal defect

Question 5

When pulmonary-to-systemic flow ratio (Qp:Qs) of a shunt exceeds _____ the shunt is considered clinically relevant, resulting in obvious volume overload of the left atrium and left ventricle

Answer 5

1.8:1 (>1:1 implies a left to right shunt)​

Question 6

What is the most consistent physical examination finding associated with a ventricular septal defect?​

Answer 6

Harsh holosystolic/pansystolic murmur loudest just below the tricuspid valve region–most defects communicate near the tricuspid valve​

Question 7

pentalogy of Fallot

Answer 7

Large, unrestrictive ventricular septal defect​
Overriding and malalignment of the aortic root​
Right ventricular outflow tract obstruction​
Right ventricular hypertrophy​
Patent ductus arteriosus

Question 8

Which echographic finding is most indicative of hemodynamically important mitral regurgitation?​

Answer 8

Circular, turgid appearance to the left atrium–often enlarged as well; indicative of volume overload and decreased function

Question 9

Define the relationship between cardiac output in the left and right ventricles

Answer 9

COleft = COright

Because they are arranged in series, cardiac output on each side must be equivalent. Therefore compensatory changes can be seen in the opposite side of the heart in unilateral ventricular failure/dysfunction.

Question 10

Incompetent valves

Answer 10

result in eccentric ventricular hypertrophy​

Question 11

Double apex sign

Answer 11

is an indicator of marked right ventricular enlargement

Question 12

Which type of adrenergic receptors predominate in the equine heart?​

Answer 12

Beta 1

Question 13

Atrial contraction is responsible for ___% of ventricular filling at rest​

Answer 13

15-20

Question 14

direct determinants of ventricular stroke volume

Answer 14

Preload (ventricular end-diastolic volume)​
Contractility​
Afterload (wall tension required to eject blood)​
Cardiac lesions increasing workload

Question 15

Frank-Starling mechanism

Answer 15

The ability of the heart to change its force of contraction in response to changes in preload

This changes stroke volume, allowing the heart to respond to systemic changes

Question 16

Systolic clicks

Answer 16

Over great vessels - benign

Over the mitral valve -thought to be a marker for MV disease or prolapse of the valve into the left atrium​

Question 17

Identify the two most common arrhythmias in the horse

Answer 17

2nd-Degree AV Block​

Sinus arrhythmia

Question 18

systolic ejection murmur

Answer 18

It is the most common functional murmur​

It must occur between S1 and S2​

It can be up to grade 4-5/6, with significant daily variation​

It is best heard over the aortic and pulmonic valves, and may project into their arteries at the left cardiac base.​

Question 19

How soon after exercise must a stress echocardiogram be performed to identify global or regional myocardial dysfunction?​

Answer 19

Up to 2-3 minutes, HR > 100 BPM

Question 20

Treatment of AF is recommended for all horses that are still in use for any type of athletic activity when the average maximal HR during sustained maximal exercise exceeds how many beats/min

Answer 20

220

Question 21

Electrical cardioversion (TVEC) involves a timed shock delivery on which ECG wave? ​

Answer 21

R

Question 22

Ventricular origin impulses​

Answer 22

Are conducted abnormally and more slowly, resulting in a widened QRS, an abnormal QRS orientation, and abnormal T waves. ​

Question 23

Junctional impulses​

Answer 23

Are more likely to result in a narrow, relatively normal-appearing QRS complex with normal initial activation and electrical axis, because they originate above the ventricular myocardium. ​

Question 24

features of complex or potentially “malignant” ventricular arrhythmias: ​

Answer 24

-severe hemodynamic compromise (systemic hypotension, poor pulse quality, -prolonged capillary refill time, weakness, collapse)​
-sustained VT​
-rapid ventricular rate (greater than 120 beats/min)​
-short coupling intervals (particularly with R-on-T complexes)​
-multiform or polymorphic QRS morphology (including torsades de pointes)​
​

Question 25

hyperkalemia

Answer 25

Broadening and flattening of the P wave are the most consistently observed change. Prolongation of the PQ interval and bradycardia develop, excitability decreases, and atrial standstill (sinoventricular rhythm) characterized by complete absence of P waves may be observed. ​
Either inversion or enlargement (tenting) of the T waves is also likely. ​
Marked widening of the QRS complex may be noted as near-lethal concentrations of potassium are approached ​