Cardiovascular disorders Flashcards
What are cardiomyopathies?
disorders that affect the cardiomyocytes or cardiac muscle function
What is heart failure? What are examples?
•Reduced ejection fraction •Preserved ejection fraction -Dilated Cardiomyopathy -Take tsubo syndrome -Hypertrophic cardiomyopathy
What is definition of heart failure?
- Heart unable to maintain adequate circulation for metabolic requirements of body
- Preserved ejection fraction (HFpEF): EF ≥ 50%, ↓ diastolic function (increase muscle mass in left ventricular) - not pharmacy - can’t relax as well
- Reduced ejection fraction (HFrEF): EF ≥ 40%, ↓ systolic function (thinning) - pharmacy - not strength to pump as well left ventricle more dilated and
What is the underlying cause of heart failure?
•Secondary to cardiac damage (ischaemia, myopathy), hypertension, valve disease
What is the effects of cardiac output and life expectancy with hart failure?
- ↓ cardiac output, venous blood accumulation
* Poor prognosis: 50% mortality rate < 5 years
What are the symptoms on heart failure?
•Symptoms - breathlessness, fatigue & fluid retention caused by cardiac dysfunction
What are ECG findings in heart failure?
- Non-specific: multiple potential ECG abnormalities linked to potential cause: e.g. Hypertrophy or Atrial Fibrillation
- Diagnosis: echocardiography & elevated natriuretic peptides
What is the definition of dilated cardiomyopthay?
•Cardiomegaly and dilation; systolic dysfunction with hypo-contraction
What is the underlying cause of dilated cardiomyopathy?
•Cause is frequently unknown; 20% - 50% is familial; secondary to anterior MI (ischaemic)
What are the effects of cardiac output and life expectancy of dilated cardiomyopathy?
- ↓Q, ejection fraction < 40%
* End-stage annual mortality of 10% to 50%
What are the investigations of dilated cardiomyopthay?
- General
•Dyspnoea, fatigue. Genetic testing. - ECG findings
•No specific features, abnormalities similar to LVH
What is the definition of hypertrophic cardiomyopathy?
•Unexplained left ventricular hypertrophy – primarily affects the interventricular septum
What is the underlying cause of hypertrophic cardiomyopathy?
•Usually familial, autosomal dominant inheritance.
What are the effects of cardiac output and life expectancy on hypertrophic cardiomyopathy?
- ↓Q
* Can cause sudden cardiac death during exercise
What investigations would be taken out in hypertrophic cardiomyopathy?
- General
•Dyspnoea, fatigue. Genetic testing. - ECG findings
•No specific features, abnormalities similar to LVH
What are the definition of tako tsubo?
•Left ventricular dysfunction where the apex balloons & symptoms mimics MI
•‘Broken heart’ syndrome
-Left ventricular enlargement in articular way
What is the underlying cause of tako tsubo?
•Stressful event, mainly affects women
What is the effect of cardiac output and life expectancy in tako tsubo?
- ↓Q, ejection fraction ~ 40%.
* 5% mortality
What are the investigations in tako tsubo syndrome?
- General
Chest pain, ↑ cardiac biomarkers. Normal blood vessels - ECG findings
ST segment elevation
Mimics myocardial infarction (but not markers)
What are conduction abnormalities?
disorders that affect bioelectrical transmission along the heart
What are atrial arryhtmias?
- Atrial fibrillation
* WPW
What are ventricular arrhythmias?
- Ventricular fibrillation
* Torsade de pointes
What are tachycardias?
- Sinus
* Atrial
What are conduction block?
- AV block (types 1, 2 & 3)
* Bundle branch block
What is atrial on ECG?
Atrial
•P-wave – atrial contraction. Normal – followed by a QRS complex
What is conduction on ECG?
Conduction
•P-R interval – conduction through AV node. Normal – between 120-200 milliseconds (msec)
What is ventricular on ECG?
- QRS complex – ventricular depolarisation. Normal – less than 120 msec
- ST segment – plateau phase. Normal – at baseline
- QT interval – total duration of ventricular depolarisation & repolarisation
- R-R interval – duration between ventricular depolarisations (heart beat)
What is positional on ECG?
•Cardiac axis – Normal – between -30 to +90 degrees
What is the definition of atrial arrhythmias?
•Disorganised electric activity and contraction
What is the underlying cause of atrial arrhythmias?
•Spontaneously active cells throughout the atria (can be associated with pulmonary veins)
What are the effects of cardiac output and life expectancy on atrial arrhythmias?
- Modest decline in Q
* ↑ risk of heart failure & stroke
What are the investigations of atrial fibrillation?
General
•Palpitations, chest pain
ECG findings
•Absent p-waves, ‘irregularly irregular’ rhythm, fibrillatory waves
What is the definitions of Wolff Parkinson White?
•Syndrome causing tachycardia & abnormal cardiac electrical conductance
What is the underlying cause of Wolff Parkinson White?
•Due to an accessory conduction pathway (the bundle of Kent) between the atria and ventricles
What is the effects of cardiac output and life expectancy of Wolff Parkinson White?
- Q unchanged
* Normal life expectancy
What are the investigations of Wolff Parkinson White?
General
•Palpitations, chest pain
ECG findings
•Pre-excitation - QRS complex of ECG & biphasic/ inverted - T-wave of ECG
What is the definition of ventricular arrhythmias?
- Arrythmia originating from His-Purkinje system or ventricular myocytes
- Ventricles contract at rates of between 150-400 bpm
What is the underlying cause of ventricular arrhythmias?
•Structural heart disease, MI or congenital
What are the effects of cardiac output and life expectancy with ventricular arrhythmias?
- Can lead to complete loss of Q
* Seconds to minutes
What are the investigations in ventricular arrhythmias?
General
•Syncope
ECG findings
•Irregular deflections, difficult to identify PQRST waves
What do the different QRS complex?
- Taller: more muscle mass within ventricles
- Wider: Slower conduction along those ventricles
What is the definition of torsade de pointes?
•Polymorphic ventricular tachycardia that occurs due to a long QT interval
What is the underlying cause of torsade de pointes?
•Congenital or acquired QT prolongation à reduced repolarisation
What are the effects of cardiac output and life expectancy of torsade de pointes?
- ↓Q
* Automatically resolves or progresses to deadly Vfib
What are the investigations of torsade de pointes?
General
•Chest pain, syncope
ECG findings
•Characteristic ‘twisting around the point’
What is definition of Tachycardias – Sinus (STach) & Atrial (ATach)?
- Atrial rate of between 100-250 bpm.
- STach – P-waves followed by QRS complexes
- ATach – P-waves not always followed by QRS complexes
What is the underlying cause of Tachycardias – Sinus (STach) & Atrial (ATach)?
- STach – Physiological
* ATach – Ectopic source of atrial beat
What is the effects of cardiac output and life expectancy of Tachycardias – Sinus (STach) & Atrial (ATach)?
- Unchanged or slightly ↓Q
* Little impact on life-expectancy
What is the investigations for Tachycardias – Sinus (STach) & Atrial (ATach)?
ECG findings
•STach – Normal
•ATach – Solitary p-waves, dependent on level of block
What is the Conduction block - AV block definition?
- Impaired electrical conduction through AV node
* Type I (Wenckebach or Mobitz I); type II (Mobitz II) & third-degree (complete) AV block
What is the underlying cause of Conduction block - AV block?
- Fibrosis or calcification of conduction system
* Type I - AV node; types II & III - His Purkinje system
What is the effect of cardiac output in Conduction block - AV block?
•Usually ↓Q
What are the investigations in Conduction block - AV block?
ECG findings
•Type I: ↑ P-R interval
•Type II: ↑ P-R interval -> 1 beat loss of AV conduction
•Type III: Complete/persistent loss of conduction from the atria to the ventricles
What is Conduction block - bundle branch block?
- Impaired electrical conduction in the right or left branches or fascicles of the bundles of His
- Right bundle branch block (RBBB)
What is the underlying cause of Conduction block - bundle branch block?
Underlying cause
•LBBB – consequence of ischaemia or heart disease
•RBBB – benign & asymptomatic
What is the effect on cardiac output of Conduction block - bundle branch block?
•LBBB – Usually ↓Q
What are the investigations in Conduction block - bundle branch block?
ECG findings
•RBBB & LBBB – Widening QRS complex > 120 msec
•Fascicle blockage (hemi-block) – Alterations in cardiac axis: posterior -> LAD & anterior -> RAD
What are Vascular: disorders that affect the blood vessels?
-Hypertension •Primary •Secondary -Myocardial infarction •NSTEMI •STEMI
What is the definition of hypertension?
•Clinic BP ≥ 140/90 mmHg & ambulatory BP daytime average ≥ 135/85 mmHg
What is the underlying cause of hypertension?
•Primary cause unknown. Various secondary causes
What are the effects of cardiac output & life expectancy of hypertension?
- Will potentially ↓Q
* Increases likelihood of heart disease or end-organ damage
What are the investigations in hypertension?
General
•Asymptomatic, requires BP monitoring
ECG findings
•No specific features
What is the definition of myocardial infarction?
•MI – Acute coronary syndrome resulting in cardiac tissue damage to coronary artery blockage
What is the definition of angia?
•Angina - Pain or discomfort that typically radiating from the chest at rest (unstable) or brought on by physical exertion or emotional stress (stable)
What is the underlying cause of MI and angia?
•Myocardial ischaemia/cell death due to coronary artery disease
What are the effects of cardiac output and life expectancy of MI and angia?
Effects of cardiac output & life expectancy
•Dependent on site but most likely ↓Q
•High mortality if untreated
What are the investigations of MI and angia?
Investigations
ECG findings
•ST segment elevation (STEMI) or normal (NSTEMI)