MI - Jacinto

7/29/2019 MI - Jacinto

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The cardiovascular system

is responsible for transporting nutrients and

removing gaseous waste from the body. This

system is comprised of the heart and the circulatory

system. Structures of the cardiovascular system

include the heart, blood vessels, and blood.



Heart A hollow, muscular organ located in the

center of the thorax where it occupies between

the lungs (mediastinum) and rests on thediaphragm. It weighs approximately 300g.

It composed of three layers: the endocardium (inner layer), the myocardium ( middle layer ),

and the epicardium ( exterior layer of the heart)

It has four chambers: the right and left atriumand the right and left ventricle



Card iac Cyc le

- refers to the events of one complete heart beat.

The length of the cardiac cycle is usually about

0.8 sec. Systo le (

contraction of the muscle)-there is ventricular pumping, the chambers of the

heart become smaller as the blood is ejected.

Occurs secondary to depolarization of cells

Diastole (relaxation of the muscle)- there isventricular filling, the heart chambers fill with blood

in preparation for subsequent ejection.



Cardiac Output Volume of blood ejected

per minute Each ventricle ejectsapproximately 70mL of blood/ beatAverages between 4-8L/min

CO = Stroke volume X heart rate =70 mlX 60 beats/min =4,200 ml/min



MYOCARDIALINFARCTION

The formation of local necrotic areas inthe myocardium. It is usually follows

sudden coronary occlusion and the abruptcessation of blood and oxygen flow to theheart muscle





RISK FACTORS

Age

Smoking

Hypertension

High blood cholesterol

Diabetes

Stress













Complications:

Acute pulmonary edema

Heart failure

Cardiogenic shock

Dysrhythmias and cardiac arrest

Pericardial effusion and cardiactamponade







Assessment and Diagnostic findings:

Patient history

12-lead ECG

Laboratory tests-serial cardiac biomarkers

-creatine kinase and its isoenzymes

-myoglobin

-troponin









Nursing diagnosis

Ineffective cardiac tissue perfusion related toreduced coronary blood flow

Risk for imbalanced fluid volume

Risk for ineffective peripheral tissue perfusion

related to decrease cardiac output



Medical Management:

Objective:

1.To minimize myocardial damage.

2.Preserve myocardial function and prevent

complications.



Pharmacologic Therapy:

Analgesics

Angiotensin converting enzyme

Thrombolytics

Emergent percutaneous coronaryintervention- this procedure is used to

open the occluded coronary artery andpromite reperfussion to the area that hasbeen deprived of oxygen.



Nursing management:

Administer oxygen

Monitor vital signs

Physical rest in bed with the backrestelevated or in a supportive chair.

Rationale: Help decrease chest discomfortand dyspnea.



Improving respiratory function

Monitor fluid volume status

Rationale: To prevent overloading the heartand lungs.

Encourage the patient to breathe deeplyand change position frequently.

Rationale: To help keep fluid from pooling

in the bases of the lungs.



Promoting adequate tissue perfusion

Bed or chair rest during initial phase of treatment.

Rationale: Helps reduce myocardial oxygen

consumption

Check skin temp. and peripheral pulsesfrequently to monitor tissue perfusion.



Reducing anxiety

Ensure a quiet environment

Preventing interruptions that disturb

sleep.

Teaching relaxation techniques

Providing emotional and spiritual support.



Invasive Coronary

Artery Procedures



PTCA (PercutaneousTransluminal Coronary

Angioplasty)

Purpose: To improve blood flow within a

coronary artery by compressing and “cracking” the atheroma.

A balloon-tipped catheter is used to open

blocked coronary vessels and resolveischemia.

Used in patient with angina and an

intervention for ACS.





CORONARY ARTERY

STENT This may be placed to overcome the

release of mediators that leads to

vasoconstriction, clotting and scar tissueformation.

Stent is a metal mesh that providesstructural support to a vessel at risk of

acute closure. The stent is positioned over the

angioplasty balloon.





ATHERECTOMY

An invasive interventional procedure thatinvolves the removal of the atheroma, or

plaque from a coronary artery by cutting,shaving or grinding.

It may be used in conjunction with PTCA.





CARDIOPULMONARYBYPASS

This procedure mechanically circulatesand oxygenates blood for the body whilebypassing the heart and lungs.

Accomplished by placing a cannula in theright atrium, vena cava or femoral vein towithdraw blood from the body.



1. The incidence of coronary artery disease

tends to be equal for men and women after the age of:

a. 45 years

b. 50 yearsc. 55 years

d. 65 years



2.The classic ECG changes that occur with

an MI include all except :

a. an absent P wave

b. an abnormal Q wavec. T wave inversion

d. ST segment elevation



3.The most common site of myocardial

infarction is the:

a. left atrium

b. left ventriclec. right atrium

d. right ventricle



4.Which of the following statements about

myocardial infarction pain is incorrect

a. It is relieved by rest and inactivity

b. It is substernal in location

c. It is sudden in onset and prolonged induration

d. It is viselike and radiates to the shoulders

and arms



5.Myocardial cell damage can be reflected by

high levels of cardiac enzymes. The cardiac

isoenzyme is:

a. alkaline phosphatase

b. creatine kinase ( CK-MB)c. myoglobin

d. troponin



6-8 NURSING DIAGNOSIS for MYOCARDIAL

INFARCTION

9-10 nursing management for patient with MI

Documents

MI - Jacinto