Cardiology Flashcards
(238 cards)
The most common arrhythmias include
Premature atrial contractions (PACs), Premature ventricular contractions (PVCs)
Four categories of arrhythmias?
- Bradyarrhythmias
- Supraventricular tachyarrhythmias
- Pre-excitation Syndromes
- Ventricular Tachyarrhythmias
Etiology of palpitations?
- Arrhythmias
- Psychiatric causes: anxiety, panic disorders
- Drugs/medications: alcohol, caffeine, over-the-counter agents (e.g., digitalis, phenothiazine, theophylline, beta agonists), street drugs (e.g., cocaine)
- Nonarrhythmic cardiac causes: Atrial or ventricular septal defect, Cardiomyopathy, Congenital heart disease, Congestive heart failure, Mitral valve prolapse, Pacemaker-mediated tachycardia, Pericarditis, Valvular disease (e.g., aortic insufficiency, stenosis)
- Extracardiac causes: Anemia, Electrolyte imbalance, Fever, Hyperthyroidism, Hypoglycemia, Hypovolemia, Pheochromocytoma, Pulmonary disease, Vasovagal syndrome
What are the drugs/medications that can cause palpitations?
Prescription drugs (eg, antiarrhythmics, digoxin, beta-agonists, theophylline, and rate-limiting drugs); over-the-counter drugs (eg, cold and sinus drugs, dietary supplements containing stimulants), including alternative medicines; and illicit drugs (eg, cocaine, methamphetamines). Caffeine (eg, coffee, tea, numerous soft drinks and energy drinks)
What should be asked on history for palpitations?
History of present illness should cover the frequency and duration of palpitations and provoking or exacerbating factors (eg, emotional distress, activity, change in position, intake of caffeine or other drugs). Important associated symptoms include syncope, light-headedness, tunnel vision, dyspnea, and chest pain.
Examples of supraventricular arrhythmias?
- Sinus Tachycardia
- Premature beats: Atrial Premature Beat, Junctional Premature Beat
- Atrial Flutter
- Multi-focal atrial tachycardia
- Atrial Fibrillation
- Atrioventricular nodal reentrant tachycardia
Examples of ventricular tachyarrhythmias?
- Ventricular Premature Beat
- Ventricular arrhythmia
- Torsades de Pointes
- Ventricular Fibrillation
Physical exam for palpitations?
- General exam + vitals
- JVP + thyroid
- Cardiac exam: rate and regularity of the rhythm as well as any murmurs
What to consider when seeing paroxysm of high BP?
Pheochromocytoma
Investigations + labs for palpitations?
- ECG
- Holter monitoring for 24 to 48 hours may be appropriate in patients with daily palpitations
- Loop recorder - Patients with very infrequent symptoms that clinicians suspect represent a serious arrhythmia
Labs:
- CBC +lytes, Mg and Ca
- Troponin (chest pain)
- TSH (hyperthyroidism)
Patients with newly diagnosed arrhythmia, findings suggesting cardiac dysfunction or findings suggesting structural heart disease require ____?
Echocardiography and sometimes cardiac MRI
What is sinus bradycardia and marked sinus bradycardia?
Sinus rhythm < 60 beats/min, but marked sinus bradycardia if <50
Causes of sinus bradycardia
- Increased vagal tone or vagal stimulation; drugs (e.g. β-blockers, calcium channel blockers); ischemia/ infarction
- Age-related degeneration of SA node = Sick Sinus Syndrome - Often associated with sudden tachycardias arising from chaotic atrial rhythms -‘tachy–brady syndrome’
What is 1st degree AV conduction blocks and who are they found in?
1° = every P wave conducts, but >200ms delay between start P & QRS. Usually benign, found in healthy individuals
What is 2nd degree AV conduction blocks?
Only a proportion of P waves conducted by AV node (2 types)
Examples of bradyarrhythmias?
- Sinus Bradycardia
- AV Conduction Blocks
Examples of pre-excitation syndromes?
- Wolff-Parkinson-White Syndrome (WPW)
- AV Re-Entrant Tachycardia
What is Mobitz I = ‘Wenckebach’?
P-waves conduct with progressive increase in PR interval. Consequence of impaired conduction within the AV node
Hallmark of Wenckebach
Grouped beating
Causes of Mobitz I = ‘Wenckebach’
Can be sign of high vagal/parasympathetic tone (e.g. athletes), can be consequence of myocardial infarct
Treatment of Mobitz I = ‘Wenckebach’
Anti-cholinergic drug
What is Mobitz II?
No preceding PR prolongation, sudden blocked P, often, fixed ratio of P’s conduct: 2:1, 3:1, 4:1 etc.
Is Mobitz II caused due to conduction disturbance proximal or distal to the AV node?
Usually due to conduction disturbance below/distal the AV node (i.e. bundle of His)
Treatment of Mobitz II?
Treatment is usually required with a pacemaker.