Cardiovascular Dysfunction Hypertensive Heart Disease Flashcards
What are some areas of CVS dysfunction?
Failure of pump
Obstruction to flow
Regurgitant flow
Shunted flow (diversion of flow from one part of the heart to another (eg. patent ductus arteriosis))
Disorders of Cardiac conduction (eg. reentry or node problems and other arrhythmia)
Rupture of heart or a major vessel (gun shot wound for example)
What happens when you have a pressure overload?
Higher systolic blood pressure which results in thickening of the walls of the ventricles. and in turn this results in concentric hypertrophy
What happens when you have a volume overload in the heart?
Increase in diastolic pressure results in addition of new sarcomeres and chamber enlargement resulting in eccentric hypertrophy
What happens to the heart after hypertrophy?
Increased muscle fiber width
Nuclear enlargement
more mitochondria in cells
Possible fibrosis (due to lower blood supply associated with hypertrophy as well as lack of increase in blood vessel size)
Synthesis of abnormal protein and additional nuclear DNA
Molecular changes (Gene expression pattern resembling foetal pattern)
What is the aetiology of cardiac hypertrophy?
Pressure or volume overload or trophic signals.
What are the causes of cardiac hypertrophy?
Hypertension (pressure overload)
Vascular disease (pressure and/or volume overload)
Myocardial infarction (regional dysfunction with volume overload)
These factors result in the cardiac work increasing thus increasing stress on the cardiac walls and the stretch of walls.
What is cardiac hypertrophy characterized by?
Increase in heart size and mass
Increase in protein synthesis
Induction of immediate-early genes
Induction of foetal gene program
Abnormal proteins
Fibrosis
Inadequate vasculature
What is cardiac dysfunction associated with?
Heart failure
Arrhythmias
Neurohumoral stimulation
What does eosinophilic tissue show on slide?
pink colour
What are the types of heart failure?
Forward failure which is a failure in tissue perfusion and results from a diminished cardiac output.
Backward failure results when there is pooling of blood in the venous system and oedema.
Left heart failure result in backward failure in pulmonary circulation and in turn right heart failure as well.
Right heart failure is secondary to left heart failure.
Systolic failure is inability to contract normally and expel blood resulting in weakness, fatigue, reduced exercise tolerance, etc.
Diastolic failure is increased resistance to ventricular inflow and reduced ventricular diastolic capacity
High output failure results from hyperthyroidism, anaemia, pregnancy, AV fistulas
Low output failure results from IHD, HHD, Dilated CM, pericardial disease
Acute heart failure occurs after big infarct valve rupture or loss of blood and usually is a type of systolic failure and results in systemic hypotension without peripheral oedema
Chronic heart failure results in multi valvular heart disease and normal BP but with oedema
How does HF appear in patients?
Dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnoea
Cachexia
Abdominal and Cerebral symptoms
Hepatomegaly
Splenomegaly
Jaundice
Hydrothorax and ascites
Peripheral oedema
What is forward heart failure?
Diminished cardiac output and reduced tissue perfusion
What is backward heart failure?
Pooling of blood in the venous system resulting in venous congestion and oedema
What is Left Heart Failure?
Congestion of pulmonary circulation causing stasis of blood in left sided chambers and hypoperfusion
What are the most common causes of Left Heart Failure?
Ischaemic heart disease (IHD), Hypertensive Heart Disease (HHD), Valvular Heart Disease (VHD), CardioMyopathy (CM)
What is the cause of right heart failure?
Secondary to LHF or primary lung disease, high pressure left to right shunt.
What does right heart failure result in?
Systemic congestion due to blood not being pumped away from the right ventricle fast enough
What is systolic heart failure?
Failure in expelling blood normally resulting in weakness, fatigue, and reduced exercise tolerance as well as symptoms of hypoperfusion
What is diastolic failure?
Increased resistance to ventricular inflow and reduced ventricular diastolic capacity (I.e inability to relax and fill)
What causes diastolic failure?
Anything that prevents the ventricle from stretching adequately to fill up. eg. Constrictive pericarditis, Cardiomyopathy, and myocardial fibrosis
What causes high output failure?
Hyperthyroidism, anaemia, pregnancy, AV fistulas, beriberi
What causes low output failure?
Ischaemic Heart Disease
Valvular Heart Disease
Dilated Cardiomyopathy
What is dilated cardiomyopathy?
Heart chamber is larger and weaker
What is acute heart failure?
The result of sudden events to the heart such as myocardial infarction, valve rupture, and loss of blood.
What type of failure typically is acute heart failure?
Systolic failure
What is chronic heart failure?
Normal BP but oedema due to slow movement of blood.
What causes chronic heart failure?
Dilated CardioMyopathy and multivalvular heart disaese
What are crepitant rales?
Cracking in lungs when breathing
What happens during Hypertensive Heart Disease?
Primarily left sided due to systemic hypertension or right sided due to pulmonary hypertension
What is the minimal criteria for diagnosis with systemic HHD?
Left Ventricular Hypertrophy in the absence of other cardiovascular pathology (very rare in the real world so flexibile criteria)
A history or pathological evidence of hypertension
What happens to people with severe hypertension?
Arteriosclerosis
Thickening of vessel wall
Fibrinoid change
Glomerulosclerosis
What are the criteria used for heart size and shape before saying a heart has undergone hypertrophy?
> 15mm and weight >500g
What is a consequence of increased left ventricular filling?
It impairs diastolic filling which results in atrial enlargement.
No dilation typically occurs but Left Heart Failure LHF can take place.
What does fibrosis in the heart look like?
Interstitial fibrosis (fine fibrosis)
Replacement fibrosis which is big patches of fibrotic tissue resulting from Myocardial infarctions
What is a problem associated with having a big heart?
Sudden death
What is pulmonary hypertension?
Elevation of pulmonary artery pressure due to pulmonary vascular or parenchymal disease. It is the right side counterpart of hypertensive heart disease.
When is pulmonary blood pressure considered hypertensive?
Pulmonary arterial pressure > 30 mmHg
What causes pulmonary hypertension?
Pulmonary vascular or parenchymal disease.
What causes pulmonary hypertension?
Pulmonary vascular or parenchymal disease.
Secondary pulmonary hypertension causes include PPH, collagen, vascular disease, congenital systemic to pulmonary shunts such as a patent ductus arteriosus.
Pulmonary venous hypertension
Lung disease and hypoxaemia
Pulmonary thromboembolic disease
What is Cor pulmonale?
Right ventricular enlargement due to pulmonary hypertension caused by disorders of the lungs or pulmomary vessels
What is acute cor pulmonale?
Massive Obstruction to flow (possibly due to Pulmonary Emboli)
What is chronic cor pulmonale?
Following long standing pulmonary hypertension as in COPD
RV thickness > 5mm As opposed to 15mm in LV
Eventually RV failure with hepatosplenomegaly and oedema
What is cor pulmonale?
abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels.
What predispose to cor pulmonale?
Diseases of pulmonary parenchyma
Diseases of pulmonary vessels
Diseases affecting chest movement
Disorders inducing pulmonary arterial constriction
What is hepatomegaly and splenomegaly?
Abnormal enlargement of the liver and spleen
Ischaemic heart disease accounts for 1/3rd of all deaths in _____ countries. Most are due to _______ narrowing of the ______ arteries.
Developed, atherosclerotic, coronary,
What are some uncommon causes of ischaemic heart disease?
Embolism from intracardiac thrombi, Disseminated Intervascular Coagulation, and arteritis
What are some types of Ischaemic Heart Disease?
Angina pectoris
Myocardial infarction
Chronic Ischaemic Heart Disease with heart failure
Sudden Cardiac death
What are the forms of angina pectoris?
Stable angina: retrosternal gripping dull pain induced by exercise or emotion and relieved by rest or nitro-glycerine
Variant form - Prinzmetal angina recurrent prolonged attacks of severe ischaemia caused by episodic focal spasm of a coronary artery. Pain at rest relieved by vasodilators
Unstable angina: Pain at rest that persists. A pre-infarct state due to partial occlusion, may have microinfarct
Tl;DR
Stable angina = Pain behind sternum when exercising or emotion.
Variant form Prinzmetal angina = Recurrent prolonged pain due to spasm of coronary artery. Pain at rest can be relieved by vasodilators
Unstable angina = constant pain behind chest that persists.
What is treatment for stable angina?
Nitroglycerine
What is treatment for prinzmetal angina?
Vasodilators
What is treatment for unstable angina?
You’re fucked at this stage
What is the pathogenesis of a MI?
Insufficient coronary perfusion.
Fixed atherosclerotic narrowing of the coronary arteries resulting in fissuring, ulceration, haemorrhage or rupture of atherosclerotic plaques
Thrombosis can potentially cause it
Tissue factor can activate the coagulation pathway.
Which part of the heart is almost always involved in a myocardial infarct?
The left ventricle
What are the types of myocardial infarctions?
Transmural
Subendocardial
What is a transmural MI?
Full thickness necrosis in area supplied by a single coronary artery
What is subendocardial MI?
Circumferential necrosis around inner 1/3 to 1/2 of the ventricular wall and may extend beyond territory supplied by a single coronary artery.
Which endocardial muscles get more blood?
Outer layer muscles tend to get their blood supply from coronary vessels better than the inner layer.
What causes microinfarcts?
Low perfusion due to heart failure
What does the extent of the myocardial infarct depend on?
Size of vessel obstructed, its site, and degree of obstruction
Rapidity of onset of the obstruction
Myocardial demand
Extent of collateral circulation
Associated arterial spasm
At what stage do macrophages come in to save the infarct?
at about 6 weeks
What happens if obstruction of coronary artery is relieved?
Reperfusion may limit the damage and give rise to eosinophilic contraction bands. It may also result in reperfusion injury due to free radical release or production of eosinophilic bands
What are the clinical symptoms of MI?
Sweating
Vomiting
Pain
What are the clinical features of a MI?
Lab tests for presence of myocardial proteins in plasma such as troponins I and T and creatine kinase
ECG changes
What are the complications of MI?
15% sudden death
No complications in 10 - 15%
the remaining 65 -
70% deal with Complications such as arrhythmias, LV congestive failure, cardiogenic shock, pericarditis, rupture of papillary muscle, aneurysms of left ventricle, thrombus formation, etc
What is chronic ischaemic heart disease?
Progressive heart failure due to ischaemic injury, either prior infarcts or chronic low grade ischaemia
Widespread atherosclerotic narrowing of coronary arteries with >=75% narrowing
What are the pathological findings with chronic ischaemic heart disease?
Widespread fibrosis (replacement and interstitial fibrosis)
Endocardial thickening
Pericardial adhesions
May have previous medical/surgical intervention
What is sudden cardiac death?
Death within 1 - 24 hours of the onset of symptoms
Usually severe multivessel disease
Thought to be due to arrhythmia
Most common cardiac cause of death in coronial population
