Cardiogenic Shock

WHAT WENT WRONG?

A drop in blood pressure and blood flow caused by the heart’s inability to pump

blood as a result of a cardiac emergency, such as cardiac tamponade, myocardial

ischemia, myocarditis, or cardiomyopathy (a disease of the heart that deteriorates

the heart muscle). Blood pools in the left ventricle, which causes a back up of blood

into the lungs, resulting in pulmonary edema. Contractions increase to compensate

for the decreased cardiac output, causing an increase in demand for oxygen by

the heart. However, the lungs are not oxygenating the blood sufficiently due to

decreased blood flow; and therefore heart muscles are starved for oxygen.

Cardiomyopathy

WHAT WENT WRONG?

The middle layer of the heart wall that contains cardiac muscle (myocardium)

weakens and stretches, causing the heart to lose its pumping strength and become

enlarged. The heart remains functional; however, contractions are weak, resulting

in decreased cardiac output. Most are idiopathic and not related to the major causes

of heart disease. The three types of cardiomyopathy are:

1. Dilated cardiomyopathy (common): The heart muscle thins and enlarges,

which leads to congestive heart failure. Progressive hypertrophy and dilatation

result in problems with pumping action of ventricles.

2. Hypertrophic cardiomyopathy: The ventricular heart muscle thickens, resulting

in outflow obstruction or restriction. There is some blood flow present.

3. Restrictive cardiomyopathy (rare): The heart muscle becomes stiff and restricts

blood from filling ventricles, usually as a result of amyloidosis, radiation,

or myocardial fibrosis after open-heart surgery.

Cardiac Tamponade

WHAT WENT WRONG?

A large amount of liquid accumulates in the sack around the heart (pericardium),

creating pressure on the heart that reduces the filling of ventricles with blood. This

results in a low volume of blood being pumped with each contraction. The accumulating

pressure within the pericardium may be due to fluid, pus, or blood. The

end result is decreased stroke volume and cardiac output.

The cause of tamponade may be trauma, postoperative, post-MI, uremia, or

cancer. The fluid may develop rapidly or over time, depending on cause. Tamponade

is a life-threatening condition. The seriousness is related to the amount of pressure

within the heart and the resulting decrease in ventricular filling.

Coronary Artery Disease (CAD)

WHAT WENT WRONG?

Cholesterol, calcium and other elements carried by the blood are deposited on the

wall of the coronary artery resulting in the narrowing of the artery and the reduction

of blood flow through the vessel. This impedes blood supply to the heart muscle.

These deposits start out as fatty streaks and eventually develop into plaque that

inhibits blood flow through the artery. Elevated cholesterol levels and fat intake

can contribute to this plaque build-up, as can hypertension, diabetes, and smoking.

When the plaque builds up within the artery, the heart muscle is deprived of oxygen

and nutrients ultimately damaging the heart muscle.

Peripheral Arterial Disease (PAD)

 

WHAT WENT WRONG?

Large peripheral arteries become narrowed and restricted (stenosis) leading to

the temporary (acute) or permanent (chronic) reduction of blood flow to tissues

(ischemia). This is most commonly due to atherosclerosis (plaque on the inner

walls of arteries), but may also be caused by a blood clot (embolism), or from an

inflammatory process. Severe peripheral arterial occlusive disease can lead to skin

ulceration and gangrene. Peripheral arterial occlusive disease is more common in

patients with diabetes or hypertension, in older adults, in those with hyperlipidemia,

and in those who smoke, as these conditions can predispose to diminished

circulation. Vascular disease that happens in one area of the body, e.g. coronary

arteries, is not an isolated process. The plaque build-up caused by long-term elevated

cholesterol levels will happen throughout the body. The most common area

of involvement is the lower extremities.

Myocardial Infarction (MI)

WHAT WENT WRONG?

Blood supply to the myocardium is interrupted for a prolonged time due to the blockage

of coronary arteries. This results in insufficient oxygen reaching cardiac muscle,

causing cardiac muscles to die (necrosis). MI is commonly known as a heart attack.

The area of infarction is often due to build-up of plaque over time (atherosclerosis).

It may also be due to a clot that develops in association with the atherosclerosis

within the vessel. Patients are typically (not always) symptomatic, but some

patients will not be aware of the event; they will have what is called a silent MI.

Angina (Angina Pectoris)

WHAT WENT WRONG?

A narrowing of blood vessels to the coronary artery, secondary to arteriosclerosis,

results in inadequate blood flow through blood vessels of the heart muscle, causing

chest pain. An episode of angina is typically precipitated by physical activity,

excitement, or emotional stress. There are three categories of angina.

Aortic Aneurysm

WHAT WENT WRONG?

A weakening in the wall of a portion of the aorta results in a balloon-like bulge as

blood flows through the aorta. The blood flow within this bulging area of the aorta

becomes very turbulent. Over time this turbulence can cause the dilated area to

increase in size, creating an aneurysm. The aneurysm can rupture causing a disruption

in blood flow to everything below the affected area, and may even result

in death.

Cardiovascular System

 

How the Cardiovascular System Works

The cardiovascular system is responsible for delivery of blood, which carries oxygen

and other nutrients, to the tissues of the body. The heart pumps the blood to

the body where it delivers nutrients and oxygen, picks up waste products, and then

returns to the heart.