CV conditions Flashcards
define cardiac failure: diastolic vs systolic
heart can’t meet O2 demands
diastolic - impaired filling
systolic - impaired pumping
What are the main causes of heart failure?
Ischaemic heart disease Hypertension Cardiomyopathy Valve defects - aortic stenosis Arrhythmias Congenital defects
Describe how long term hypertension may lead to heart failure
long term hypertension leads to hypertrophy of myocardium in order to pump harder to overcome the increased arterial pressure in systemic circulation. These larger cells have greater metabolic demands for O2 and so contraction weakens (systolic L HF) *and there is less room for filling (diastolic)
Who is at risk of cardiac failure?
African descent Obese Previous MI Hypertension age 65+ Male
How may an individual with heart failure present?
SOB Fatigue Ankle swelling Dyspnoea Ascites Jugular venous distension Cyanosis
- depending on how far along and whether biventricular
What blood test is used in an individual with suspected heart failure?
If levels were elevated, what other test may you use?
Brain natriuretic peptide: levels correlate with severity.
If levels are raised and ECG is also abnormal, use echocardiography to confirm
Treatments for cardiac failure
- Lifestyle modification
- Meds:
Ace-i eg ramipril or ARB eg candesartan
Beta blocker eg bisoprolol
Digoxin/Inotropes
Diuretics for symptomatic treatment of congestion - furosemide
Aldosterone receptor antagonists eg spironolactone - Revascularisation, surgery eg if cause is valvular, heart transplant in some cases
Peripheral vascular disease cause risk presentation diagnosis treat
Organic (due to a blockage):
atherosclerosis, embolus
Functional (due to constriction)
vasospasm
Risk:
men, obese, smoking, hypertension, diabetes, hyperlipidaemia, age
Presents with intermittent claudication (cramping pain when exercising), elevation pallor/dependent rubor, ulcers that don’t heal normally. If progresses, individual develops critical limb ischaemia: rest pain typically nocturnal, relieved when foot lowered off bed, gangrene - tissue necrosis.
Diagnose
absent/whooshing femoral/popliteal/foot pulse, doppeler USS, ankle-brachial pressure index provides measure of severity and risk of critical limb ischaemia
Treat
lifestyle, underlying conditions
p2y12 inhibitor clopidogrel antiplatelet
Revascularisation in some cases by percutaneous transluminal angioplasty
describe the treatment steps for hypertension
- ACE-i such as ramipril (ARB if contraindicated), or Ca channel blocker such as amlodipine if over 55/afro-caribbean
- Ace-i (or ARB) + CCB
- ACE-I (or ARB) + CCB + thiazide-like diuretic such as bendroflumethiazide
- = resistant hypertension
add aldosterone antagonist/k+ sparing such as spironolactone, increase dose of thiazide-like, or add alpha/beta blocker
Atrial Fibrillation - what? Diagnosis Risk factors Symptoms Complications
Signals are disorganised and override the SAN leading to lots of mini contractions. Not all make it to the ventricles.Twitching, absent P wave and irregular QRS complex on ECG.
May be paroxysmal (lasts 48hrs), peristant (lasts 7 days), long standing persistant and permanent.
Common in individuals with other heart conditions - CAD, hypertension, valvular disease, obesity, diabetes, excessive alcohol. Could stress heart leading to tissue heterogeneity.
May be asymptomatic, or SOB, dizzy, palpitations, fatigue, syncope.
Complications: lots of mini contractions means blood stagnates and clots in the atria, from which they may be pumped to the body/brain causing stroke or embolism.
Treatment of AFib?
- Pharmacology: aim to control heartrate and reduce clotting
Amiodarone
Beta blocker (bisoprolol)
Ca channel blocker (amlodipine)
Digoxin
Warfarin/anticoagulant to reduce clotting risk - Cardioversion: controlled shock aims to return normal rhythm
- Catheter ablation: radiological destruction of diseased area to interrupt abnormal circuits
- Pacemaker
What is atrial flutter and how does it differ from AFib?
Atria contract at high, regular rates as opposed to the random contractions of fib.
Reentrant signal loops back and overrides SAN, starting continuous cycle of contraction.
Less common, associated with fib.
Cause of atrial flutter
Idiopathic (30%) • Coronary heart disease • Obesity • Hypertension • Heart failure • COPD • Pericarditis • Acute excess alcohol intoxication
Associated with atrial fibrillation.
What ECG is characteristic of an individual with atrial flutter?
Symptoms of atrial flutter
Treatment
Regular jagged P waves: sawtooth pattern.
Ratio of atrial : ventricular beats clearly visible.
SOB, dizzy, nausea, palpitations, syncope
Anticoagulate with low dose heparin
Cardioversion
Catheter ablation
amiodarone to restore sinus rhythm
bisoprolol to reduce strain on heart from ventricles decompensating
What is atrioventricular reentrant tachycardia? Most common example?
An accessory pathway in the heart allows signals which have passed through bundle of His to reenter atria and cause contraction before SAN has finished refractory period, leading to periods of tachycardia.
Individuals with Wolff Parkinson-White syndrome have an anatomical accessory pathway.
Treatment of Wolfff Parkinson-White?
Catheter ablation
What is meant by heart block ? Common causes?
Signals are delayed/blocked. Usually due to damage/fibrosis.
Causes can be past MI, idiopathic, and more rarely myocarditis/cardiomyopathy.
What is AV block?
How is it treated?
Signal block between atria and ventricles.
There are 3 forms, 1st 2nd and 3rd degree block.
Treatment of underlying cause, medications to increase HR, sometimes pacemaker fitted.
Describe 1st degree AV block: causes, symptoms, treatment?
Causes:
- Hypokalaemia
• Myocarditis
• Inferior MI
• Atrioventricular node (AVN) blocking drugs e.g. beta blockers (Bisoprolol), calcium channel blockers (amlodipine) and digoxin
Lond PR interval whereby signal is delayed but makes it eventually. Asymptomatic so not treated.
Describe 2nd degree AV block: types, symptoms treatment
2 types:
Mobitz 1. PR interval becomes progressively longer until blocked completely (dropped beat) - whereon ventricular escape beat will initiate after 2 secs. Dizzy/syncope/light-headed. Pacemaker not necessary
Mobitz 2. Caused by Intermittent dropped beats, no progressive lengthening
Symptoms: SOB, postural hypotension and chest pain
• High risk of developing sudden complete AV block, and a pacemaker should be inserted
Describe 3rd degree AV block: symptoms, treatment
Signal is blocked completely, does not conduct to ventricles - P waves completely independent of QRS complex. Ventricles contract with slow escape beats.
Symptoms: syncope, confusion, dyspnoea, severe chest pain. Risk of death.
What is bundle branch block?
treatment?
The bundle of His divides into right and left bundle branches. If either of these is blocked, there is delayed contraction of R or L ventricle.
May be present from birth, if asymptomatic no treatment. Some acquired from CHD and accompanied by HF, pacemaker may be necessary.
Causes of bundle branch block, acute and chronic
acute: ischaemia, MI, myocarditis
chronic: hypertension, coronary artery disease, cardiomyopathies
How is a R bundle branch block differentiated from a L bundle branch block?
ECG traces:
WiLLiaM: QRS looks like a W in leads V1 & V2, QRS looks like an M in leads V4-V6 = L bundle branch block
MarRoW: QRS looks like an M in lead V1
• W - QRS looks like W in V5 & V6. = R bundle branch block
