Vet Sci 4Cardiology, CPCR

Internally between the 3 & 6th intercostal space, more on the left behind the Left elbow

1) Pericardium- outermost sac, covering surrounding the heart
Has 2 layers that make it up. FIBEROUS Layer-the tough sac
SEROUS layer- secretes serous fluid to decrease friction from beating heat within the chest cavity.
2) EPICARDIUM- outer lining of heart
3) MYOCARDIUM-muscular layer, largest portion of the heart
4) ENDOCARDIUM-innermost layer, tissues that line the chambers

*ventricular systole the contraction of the cardiac ventricles by which blood is forced into the aorta and pulmonary artery.

The normal rhythmically occurring RELAXATION and DILATION of the heart chambers, especially the ventricles, during which they fill with blood.

Both AV valves (tricuspid and Bicuspid)

Pulmonic and aortic valves are open

During the relaxation/dilation phase of the cardiac cycle, the AV valves, Tricuspid and bicuspid open and allow blood to fill the ventricles

Pulmonary valve and aortic valve close during diastole while the ventricles fill.

1) Brings oxygen and important nutrients to tissues throughout the body.
2) Waste products are removed from the body
3) Endocrine system function and transporting of these important hormones.

Mass of specialized cells located in Right atrium near cranial vena cava
*Often called the PACEMAKER
*generates electrical impulses and initiate conduction which causes heart to contract in a regular set rhythmic rate.

*Continuously pumping blood with enough force to maintain bp for circulation throughout the body.

After the SA node fires an impulse that flows across the atria, it localizes at this node, which then holds the impulse for a moment to allow ventricles to fill completely, then moves to Bundle of HIS

Purkinje fibers

The AV node and Purkinje fibers can fire/generate impulses, however, the further along the system these impulses are generated, the slower the heart rate.

The recording of electrical changes that occur in the myocardium during a cardiac cycle.

By hooking up electrodes on the skin in a particular pattern to trace the spread of electrical activity within the heart.

Each different angle is called a lead. It is a particular view of electrical activity of the heart. It is similar to DV or lateral views in radiographs.

Lead II view

Lead systems allow you to look at the heart from a variety of angles

Right lateral recumbancy

*on a blanket if placed on a metal table

perpendicular

Parallel

WHITE- Right axillary
GREEN- Right inguinal
BLACK-Left axillary
RED-Left inguinal
BROWN-chest

The depolarization of the atria and its duration indicates the time required for an impulse to pass from an SA node to the AV node.
**ALWAYS POSITIVE on the ECG

Represents Systole-ventricular depolarization/contraction

-Q or S may be absent and it is still considered normal

Represents Diastole-ventricular repolarization/relaxation

Can be positive or negative but should be consistant

distance between 2 R waves and should be consistent

Distance/time between P wave to R wave.
* It is the Atrial contraction to beginning of ventricular contraction. Represents atrial filling

It represents the end of systole/ventricular contraction.

It shows the period of time between completion of ventricular contraction and beginning of ventricular repolarization.

ANY deviation from normal rhythm of the heart. Can be a variation of rate, regularity, site of impulse origin.

1) GENERAL INSPECTION-fast, slow, pattern to irregularities or completely irregular
-Obtain HR
2) ANALYZE P WAVES--Regular and -P Wave before every QRS
3) ANALYZE-QRS complexes
* reg in apperance, uniform interval
*All parts present
* Normal in width (time)
* Should be quick
4) RELATIONSHIP of P waves to QRS complexes

20

10

electrical activity is traveling normally

Normal sinus rhythm = normal heat rhythm

More detail

extra heart sound

area of turbulent blood flow causes an extra heart sound

Systole, AV valves closing, Ventricular contractions

Diastole/ventricular relaxation, AV valves opening

during systole with the pulse

LUBB---shhhhhh---DUBB
S1 S2

Most murmurs are systolic

Diastole or AFTER pulse, S2

LUBB-DUBB ----shhhhhhh--LUBB--DUBB------Shhhhh

Valvular insufficiency
Valvular Stenosis
PDA-Patent Ductus Arteriosis

AV valves are not closing completely or efficiently when the ventricles contract which results in a backflow of blood into the atria.
*Most common type of murmur
*Rarely affects Pulmonary or atrial valves
*considered a DIASTOLIC MURMUR

*stricture, narrowing of valves
*Aortic and Pulmonary valves most commonly affected
*Reduces amount of blood that is able to be pumped to ventricles--->increases pressure in heart because not all blood that should be pumped out is actually pumped out.

In PDA, abnormal blood flow occurs between two of the major arteries connected to the heart.

Before birth, the two major arteries—the aorta and the pulmonary artery—are connected by a blood vessel called the ductus arteriosus. This vessel is an essential part of fetal blood circulation.

Within minutes or up to a few days after birth, the vessel is supposed to close as part of the normal changes occurring in the baby's circulation.

In some babies, however, the ductus arteriosus remains open (patent). This opening allows oxygen-rich blood from the aorta to mix with oxygen-poor blood from the pulmonary artery. (a left to right shunt) This can put strain on the heart and increase blood pressure in the lung arteries.

Pulmonary edema, exercise intolerance, weight loss, CHF

Sx
Application of a self closing band

6 levels and 6 is the worst

*A very soft localized murmur
*Can be detected only after intense listening

A soft murmur
May be heard immediately

Low to moderate intensity murmur
Can be heard over a wider area

Moderate to loud intensity murmur heard over most of heart.
Does NOT have a precordial thrill (palpable heatbeat)

Loud murmur with a precordial thrill

A loud murmur w/a precordial thrill that is audible when stethoscope is liftted off chest wall

5 & 6

The volume of blood ejected from the heart during each contraction/heartbeat/systole

is the volume of blood pumped by the heart per minute.
It is figured by HR times Stroke volume

The pressure stretching the ventricle after passive filling and and atrial contraction.
-affected by Venous bp & return
*before respiring, how much blood is getting into atria

A measurement used to measure the tension produced by a chamber of the heart in order to contract.

Pressure chamber has to generate in order to eject blood out of the heart.

* Increase heart rate by 2-3x

*Hypertrophy- chronic overworked heart muscle heart hypertrophies

*Dilation of chambers-walls of ventricles get thinner, heart muscle mass decreases, is less effective. Tries to let more blood in to compensate for lack of cardiac output.

Lethargic
Tachycardia
Tachypnea
Exercise intolerance
Cough-dry, unproductive cough

Cynosis
Cachexia
Orthopnea
Ascites
Pulmonary edema

Physical wasting with loss of weight and muscle mass caused by disease

tendency towards postural positioning as the animal tries to get front end higher to relieve pressure from ascites.

fluid buildup in the abdomen as a reult of right heart failure?s

Fluid buildup in the lungs as a result of left sided heart failure

*Auscultation
*Echocardiography
*BP-Doppler evaluation of Norm is 80-120 mm of Mercury
*Blood gas eval
-CO2, O2, Pulse Ox machine evals how much of hemoglobin is saturated with O2
* Radiographs-size, fluid buildup
* ECG-check electrical activity

PDA
Septal defects
-Atrial septal fects
-Venticular septal defect
Aortic & Pulmonic stenosis

* AV VALVE INSUFFICIENCY
Valve(s) atrophy and no longer meet and/or Chordae tendinae ruptures and no longer holds valves right
*HEARTWORMS-obstruction of pulmonary artery leads to Right heart failure
*VEGATATIVE ENDOCARDITIS-Gram +, Bacterial infection leads to settling on AV valves
*HYPERTROPHIC CARDIOMYOPATHY-muscle thickens, less room in chambers, more common in cats, can be somewhat genetic.
*DIALATED CARDIOMYOPATHY- Expanded heart chambers to try to accept more blood, heart muscles thin and weaken, More common in dogs (GSD, Cockers, Boxers, dobies, Danes)
*PERICARDITIS-inflammation of pericardium due to infection-can be viral, bacterial, fungal in origin. Other causes are kidney failure, metastatic disease, trauma, idiopathic

Poor dental prophalaxis and major dental disease

Mufffled heart sounds

Inotropes
Chronotropes
Anti-arrhythmics
Vasodialators

Affect how the heart contracts, + is harder, - is softer contractions

affect the heart rate
Positive chronotropes increase, negative chronotropes decrease heart rate

Calms the nerves and muscles in the heart to allow normal electrical activity

Ventricular tachycardia in cats

Decreases heart rate, lengthens time between action potentials in ventricular tachycardia treatment

the sympathetic nervous system, fight or flight division

Enapril
Medications that slow (inhibit) the activity of the enzyme ACE, which decreases the production of angiotensin II. As a result, the blood vessels enlarge or dilate, and blood pressure is reduced. This lower blood pressure makes it easier for the heart to pump blood and can improve the function of a failing heart.

It is a diuretic that reduces blodd volume and lessens the hearts workload

It is a cough suppressant that is given to animals with a heart that enlarged to the point of irritating the trachea.

Cardiopulmonary Cerebrovascular Resuscitation

Cardiopulmonary arrest

Not breathing or trying to
MM discolored
NO pulse
No heartbeat heard
Pupils fixed and dilated

Hypoxia
Metabolic disorders
Trauma
Anesthetic or other drugs
Environmental influences such as toxins or extreme temperatures

*Pre-arrest condition -healthy, sick, geriatric
*Time elapsed since arrest
*Etiology of arrest
* Effectiveness of cardiac massage
*client wishes

BASIC LIFE SUPPORT-Airway, breathing, heart compressions
ADVANCED LIFE SUPPORT- drugs and defibrillation
PROLONGED life support-Fix primary cause, monitor for 2nd arrest, 24-48 hrs at least

Support cardiovascular system and provide ventilitory support until body can do it on its own

*Airway management-open patent airway established, maintained.
*Cardiovascular management
* Venous access-cath placed
* Monitoring
Drug Administration

*CIRCULATORY supplies-cath, tourni, t-ports, injection caps, heprinized flush, fluids
*AIRWAY & BREATHING supplies-ET tubes, +/- laryngescope, stylets, suction, ambubag
*DRUGS- Epinephrine, Dextrose, Atropine, Lidocaine, DMSO

* Decreased mentation, lack of response
*Respiratory changes, depth, pattern
*Pulse changes-rhythm, quality, missing, thready
*Abnormal ECG patterns
*Unexplained changes in anesthetic depth

*Check for femoral pulses
*listen for heart sounds
*Palpate apical beat
*If under GA, turn off anesthetic gases immediately
*Notify appropriate personnel
*Once verified, begin CPCR

* A-airway, ensure patent airway, ET tube, tracheostomy
* B-Breathing-ventilating with 100% O2, 15-20 cm H2O pressure if on anesthesia machine or 2 breaths of 1.5 seconds each initially.
Ventilation rate: 1 breath per 3-5 compressions given concurrently
* C- CIRCULATION/Cardiac massage: 80-120 compressions/minute
-compress and release-each for count of 1
-check for adequate femoral pulses-should be felt if compressions are adequate/effective
D-DRUGS/Defibrillation- place IVC, may apply compression wraps, Defib charged and ready to go

1 breath per 3-5 compressions

Preferred Right lateral recumbancy
-Dorsal is ok in barrel chested dogs over 30 lbs

-Compress mid-thorax with elbows locked
-Check rhythm with ECG
-If external is ineffective after ~5 minutes, internal may be done

Initial dosage:
dogs 70-90 mls/kg
cats 40-60mls/kg
*Administer as a bolus-wide open

#1-Jugular
#2-IT, Atropine, Lidocaine, Epinephrine
#3-Peripheral - cephalic
IC becoming less common
IO

May reverse RESPIRATORY arrest

-needle is inserted at nasal philtrum just below nose. all the way to the bone and the twirled and moved up and down.