part 5 Flashcards
Congestive heart failur is also considered to be a form of what?
A decompenstaed heart.
What type of condition is congestive heart failure?
chronic condition.
What are the physciological findings of congestive heart failure?
Failure of the law of the heart. More blood in does not give us more blood out anymore.
Where will blood backup into with congestive heart failure?
commonly in lungs and periphery like the ankels, and feet.
People with congenstive heart failure get fatigued due to what?
decreased cardioac output.
what is CAD?
Coronary artery disease.
What is CAD a major source for?
Congestive heart failure.
What is A-V heart block due to?
An arrhythmia due to a blockage in the electrical conduction system.
What are the subtypes of A-V heart block?
1st degree- mild interruptions, second degree- moderate interruption, third degree- severe interruption/disruption.
How common are the different types of A-V heart block, and what symptoms will they have?
First degree is common and symptom free. Second degree is less common and causes irregular heart beats, thrid degree is a complete disruption and results in cardiac output problems.
What are the laboratory findings for A-V heart block?
Abnormal ECG.
How will all heart cell contractions originate?
With a myocyte action potential.
Since each cardiac cell has its own unique action potential that allows them to spontaneously depolarize and impulse and then propagate this to the neighboring cells how will the heart not get out of control?
It has a wiring system called the conduction system.
What makes cardiac conduction system cells different from cardiac muscle cells?
They lost ability to contract a lot, but can conduct depolarization impulses rapidly.
What region of cardiac muscle cells is fastest to recycle (have a short refractory period)?
SA node.
Because the SA node is fastest at recycling what will it be able to do?
It usually leads the pack and is known as the pacemaker because it produces a sinus rhythm.
What else besides the SA node can become the pacemaker of the heart?
Any patch of cardiac tissue that fires faster than the SA node.
Why will cardiac muscle cells usually not mis-fire (impulsing before the SA node)?
They have a longer refractory period.
What happens when the SA node is stretched?
It tends to fire faster and increase the heart rate.
Will contraction impulses spread faster across the atria or ventricles?
Faster across the atria.
What will the fibrous skeleton do with the electrical impulses?
It will prevent it from leaking into ventricles except at the AV node.
What will the AV node do to the impulse propagation?
It holds it up for 1/10th of a second.
Why is the impulse delayed at the av nodes?
it allows the atria to have enough time to physically contract before ventricles contract allows them to be topped off.
Besides creating a pause in the impulse propagation what will the AV node do to the electrical impulse?
It wont allow it to go backwards a one way street.
What will the parasympathetic and sympathetic stimulation do to the SA and AV nodes?
Paraympathetic- hyperpolarizes the SA and AV nodes, Sympathetic- hypo-polarizes the nodes.
What is the electrocardiogram?
a display from a supersensitive voltmeter called and electrocadiograph.
What will an electrocardiogram represent?
a collective voltage of thousands of cells.
What will the ECG’s P wave correspond to?
atrial depolarization.
What will the ECG’s QRS complex correspond to?
Ventricular depolarization.
What will the ECG’s T wave correspond to?
Ventricular repolarization.
What will the Q wave from the QRS complex correspond to?
Depolarization of the emerging bundle of AV nodes.
What will ther R wave from the QRS complex correspond to?
Rapid depolarizatoin of the ventricles.
What will the S wave from the QRS complex correspond to?
rapid reversal of the impulse directoin at apex and now towards the base.
The QRS complex happens real fast and what will it mean if it is not smooth or slow?
indication of a serious problem in the ventricles.
What is the flat line on the ECG called?
A segment.
What is a combination of waves or wave segment on an ECG?
Interval.
What is the PR segment of an ECG due to?
AV nodal slowdown.
What is the ST segment of an ECG due to?
IT is during the absoluted refractory period.
Why would the ST segment be examined?
To see if there is serious problems in the muscle cells of the ventricles.
How did the pr segment get its name?
Beacuse this happens when the Q wave is absent.