CVD II - HF and Valv HD Flashcards
what are the functions of the SA node
- primary pacemaker
- regulates atrial function
- produces P wave - atrial depolarization
what is the function of the AV node
- regulates atrial impulses entering ventricles
- slows conduction rate of SA generated impulses
what is happening during the QRS complex
simulataneous depolarization of the ventricles
what happens during the T wave
repolarization of the ventricles
disruption of the electrical impulse generation or conduction in the heart leads to what abnormal cardiac functions
- formation of abnormal impulse
- increased impulse formation
- enhanced or abnormal impulse formation
- delayed depolarization
- re-excitation of the heart after refractory period
disruption of the electrical impulse generation or conduction in the head may be due to an area of:
- infarction
- ischemia
- electrolyte imbalance
- medication
the most common cause of sudden cardiac death is:
ventricular fibrillation
what are the causes of arrhythmias
- cardiovascular disorders
- pulmonary disorder
- autonomic disorder
- hyperthyroidism
- drugs
- electrolyte imbalance
- anxiety and anger
what cardiovascular disorders cause arrhythmias
- MI
- mitral stenosis
- valvular disease
- ischemic heart disease
- congestive heart failure
what pulmonary disorders cause arrhythmias
-pneumonia
- obstructive lung disease
what drugs cause arrhythmias
- epinephrine
- alcohol
- digitalis
- morphine
- beta blockers
- tricyclic antidepressants
what are the supraventricular arrhythmias
- sinus nodal disturbances: sinus arrhythmias, sinus tachycardia, sinus bradycardia
- disturbances of atrial rhythm: premature atrial complexes, atrial flutter
- ventricular tachycardia
- ventricular fibrillation
what qualifies bradycardia
less than 60 beats/min
what qualifies tachycardia
greater than 100 bpm
what are the symptoms of arrhythmias
- palpitations, fatigue
- dizziness, syncope, angina
- CHF
- SOB
- orthopnea
- peripheral edema
describe atrial fibrillation
- most common arrhythmia
- rapid uncontrolled atrial activity
- irregularly irregular rhythm
- risk of arterial clot formation: embolism and stroke
what is a heart block
- impulse is partially or completely blocked
- prolonged or no conduction
what are the degrees of heart block and describe each
- first degree: longer conduction time
- second degree: Mobitz I: more prolonged and no P wave. Mobitz II: repetitive or occasional sudden blocks without previous prolonged conduction time
- third degree: no impulses- complete block. indication for pacemaker
describe ventricular arrhythmias
- premature ventricular complexes (PVCs)
- common
- abnormal QRS complex + pause
- increased risk of death if patients have underlying CVD ( heart failure, MI, valvular heart disease)
describe ventricular tachycardia
- if more than 3 consecutive PVS at 100 bpm
- if lasts for more than 30 seconds, requires termination
- torsades de pointes- potentially life threatening
describe ventricular flutter and fibrillation
- lethal
- consequence of ischemic heart disease
- cardiac contraction is not sequential, chaotic
is there tx for arryhthmias
no just aimed at managing symptoms
what are the SE for sodium channel blockers
- bitter taste
- dry mouth
- oral ulcerations
what are the SE of beta blockers
taste changes, lichenoid reactions
what are the SE of potassium channel blockers
- taste abberation
- lichenoid reactions
- angioedema
what are the slow calcium channel blockers
gingival overgrowth
what are the oral anticoagulants
- clopidogrel (Plavix): inhibits platelet agglutination. platelet count not affected
- ASA (aspirin 81mg- low dose): inhibits platelet agglutination, platelet count not affected
- warfarin: vitamin K antagonist, INR monitoring, highly variable
what do anticoagulants do for arrythmias
lower the risks of complications but dont control the arrythmias
what creates opportunities for atherosclerosis and blood clotting
turbulent blood flow and failure to move blood from the atria to the ventricles
what is the therapy for A-fib
to control ventricular rate
- diltiazem ( calcium channel blocker) slows AV nodal conduction as too many electrical signals coming from the fibrillating atria are hitting the AV node per unit time
what are the direct oral anticoagulants
- direct thrombin inhibitor: pradaxa, reversal agent available
- direct factor Xa inhibitors: Xarelto, Eliquis, Savaysa, reversal agents not available
never stop anticoagulation for dental treatment unless:
extensive surgery
what are the non pharmacologic treatments for arrhythmias
- pacemakers
- implanted cardioverter defribrillator: sets pace and shocks
- surgery: tissue resection, cardiac ablation, surgery to address underlying cause such as stenosis
- electrocardioversion and defribrillation: emergency situations, terminate persistant, refractory or lethal arrhythmias
what are the dental treatment considerations with arrhythmias
- what type of arrythmia
- assess comorbidities - CVD and pulmonary
- ROS: palpitations, chest pain, dizziness, shortness of breath, syncope
what are the causes of heart failure
- decreased pumping action
- systemic fluid congestion
- failure of vital organs
what are the results of right side HF
- pulmonary edema
- coughing
- peripheral edema
what are the results of left side HF
- affects all organ systems; decreased kidney function contributes to fluid retention
- pulmonary edema
- coughing