Complications of heart disease Flashcards
Which half of the heart contains oxygenated blood?
Left
In what order do ion channels cycle during an action potential of the heart?
Na channel opens/closes v quickly Ca channel opens, ions enter cell K+ Cl- opens, leaves cell K/Na ATPase Na/Ca pump
Name the three conformational states of an ion channel
Resting
Activated
Inactivated
What are the main causes of cardiac arrhythmias?
Abnormal pacemaker activity and/or cardiac conduction
True/False? Drug toxicity is one of the many risk factors for Cardiac arrhythmias
True
What are the three treatments for arrhythmias
Electrical devices
Electrical ablation of abnormal pathways
Drug treatment
Name 3 ways to slow normal pacemaker activity
1) more negative diastolic potential
2) reduction of diastolic depolarization
3) more positive threshold potential
True/False? A small difference in threshold potential is enough to have a large impact
True
What are two examples of abnormal pacemaker activity that lead to cardiac arrhythmias?
Early afterdepolarization (due to prolonged plateau)
Delayed afterdepolarization (calcium overload)
Which of the two abnormal pacemaker activities arises from the plateau as opposed to the resting potential?
Early afterdepolarization
What happens when there is a disturbance of cardiac conduction?
The action potentials don’t cancel each other out at the ventricular wall and re-entry occurs
Exacerbates the situation and causes ventricular fibrillation (fatal)
True/False? Anti-arrhythmic drugs are relatively safe to use
FALSE, very low therapeutic index (killed more than placebo)
What are the 3 types of Na channel blockers and how to they work?
All delay action potential by slowing the heart
1A: Slow intraventricular conduction (increase QRS) and increase ventricular AP (increase QT)
1B: Selective for abnormal tissue
1C: slow intraventricular conduction only
How do beta blockers work as antiarrhythmic drugs?
Slow AV conduction and prolong PR interval
How to IKr channel blockers work as antiarrhythmic drugs?
Prolong ventricular AP therefor prolong PR interval
How do L-type calcium channel blockers work as anti-arrhythmic drugs?
Slow AV conduction therefore prolongs PR interval
What are three effects of diabetes on cells?
Macrovascular disease: gangrenous, might require amputation
Microangiopathy: thickening of basement membranes (might go blind)
Chemical: thickening of wall
True/False? Side effects of some CV drugs include hyperglycemia and Diabetes Mellitus
True
How can diuretics cause hyperglycemia?
Depletion of K+, inhibiting insulin secretion
What are the 5 types of embolism?
- Arterial embolism (dilated left atrium) -> femoral artery
- Venous embolism (deep veins of calf) -> block of pulmonary trunk
- Amniotic fluid embolism (amniotic fluid in blood during pregnancy)
- Air/gas embolism (after pregnancy/injury, air enters circulation)
- Fat embolism (Complication of fractured long bone)
What is the category of class I antiarrhythmic drugs? Give an example
Na Channel Blockers
e.g. Quinidine
What is the category of class II antiarrhythmic drugs? Give an example
Beta Blockers
e.g. Propranolol
What is the category of class III antiarrhythmic drugs? Give an example
I(Kr) channel blockers
e.g. Sotalol
What is the category of class IV antiarrhythmic drugs? Give an example
L-Type Ca2+ channel blockers
e.g. Verapamil
What is the category of class V antiarrhythmic drugs? Give an example
Miscellaneous (other)
e.g. Adenosine