Module 2: Cardiovascular disorders Flashcards
What is hypertension?
Chronically elevated blood pressure with a systolic pressure of 140mmHg or above or a diastolic pressure of 90mmHg or above
If other risk factors are present, a BP of 135/85 is classified as hypertension.
What are the two types of hypertension?
- Primary (essential) hypertension
- Secondary hypertension
What is hypotension?
Low blood pressure, defined as systolic pressure below 100mmHg
Usually no cause for concern.
What factors cause an increase in Mean Arterial Pressure (MAP)?
- Increase in cardiac output
- Increase in peripheral resistance
What mechanisms regulate blood pressure?
- Renin angiotensin aldosterone system
- Natriuretic Peptide (ANP & BNP) Release
- Antidiuretic hormone (ADH)
- Regulation of blood volume
What triggers the release of renin?
Low blood pressure
What is the role of angiotensin II?
- Causes systemic vasoconstriction
- Stimulates renal salt and water retention
- Stimulates tissue growth and inflammation
What is the impact of aldosterone release?
- Increased sodium reabsorption
- Increased water reabsorption
- Increased blood volume
- Increased blood pressure
How does ANP affect blood pressure?
Helps reduce blood pressure by decreasing renin release and inhibiting ADH and aldosterone release
What is primary hypertension?
90% of cases of hypertension with no identifiable underlying cause
What are common risk factors for primary hypertension?
- Heredity
- High salt intake
- Obesity
- Age (post 40 years)
- Diabetes mellitus
- Stress
- Smoking
- Excessive alcohol intake
What is secondary hypertension?
10% of cases with an identifiable cause such as renal failure or pregnancy
What are the effects of hypertension on the body?
- Promotes atherosclerosis
- Damage to endothelium of blood vessels
- Thickening of arterial walls
- Decreased lumen leading to increased peripheral resistance
Fill in the blank: Control of primary hypertension includes lifestyle changes such as _______.
restriction of salt, fat, and cholesterol intake
True or False: Secondary hypertension can be cured by resolving its underlying cause.
True
What is the relationship between hypertension and heart failure?
Uncontrolled hypertension can lead to heart failure
What is the role of ANP in blood pressure regulation?
Released by ventricles and helps reduce blood pressure
What are some rarer causes of severe hypertension?
- Aortic coarctation
- Phaeochromocytoma
- Cushing’s syndrome
- Conn’s syndrome
What is myocardial infarction commonly known as?
Heart attack
Myocardial infarction results from the death of heart muscle due to a blockage of a coronary artery.
What does ischaemia refer to in the context of myocardial infarction?
Deprivation of oxygen to the heart muscle due to blockage
Ischaemia leads to injury and may result in irreversible death of heart muscle.
What is the primary cause of ischemic heart disease?
Imbalance between myocardial blood flow and metabolic demand
Usually related to progressive atherosclerosis.
What are common risk factors for atherosclerosis?
- Increasing age
- Smoking
- Kidney disease
- Being male
- Lack of exercise
- Obesity
- High blood cholesterol
- Diabetes
- Hypertension
- Stress
- Family history
These factors contribute to the development of atherosclerosis.
What initiates the development of atheromas?
Damage to the endothelium of an artery
This damage stimulates an immune response and inflammatory reaction.
What are foam cells in the context of atheroma development?
Macrophages that have taken up lipids and transformed
Foam cells accumulate and contribute to the formation of fatty streaks.
What is angina pectoris?
Severe pain caused by fleeting deficiency in blood delivery to the myocardium
It occurs due to ischemia but does not result in cell death.
What distinguishes myocardial infarction from angina?
Infarction results in death of myocardial cells
Angina does not cause cell death and can be relieved by rest.
What is the significance of a 12 lead ECG in diagnosing myocardial infarction?
It identifies the areas of the heart involved and anticipates complications
A raised S-T segment in leads indicates MI.
What is the treatment option for a myocardial infarction if the plaque is still soft?
Angioplasty or stent insertion
These procedures help restore blood flow in blocked arteries.
What is heart failure?
When the heart fails to pump sufficient blood to meet the body’s needs
It may involve left and/or right ventricles.
What is left ventricular failure commonly caused by?
Myocardial infarction
It leads to back pressure on the lungs and may result in pulmonary edema.
What happens during right ventricular failure?
Blood backs up in the venous system
It leads to systemic symptoms like peripheral edema.
What are the two types of heart failure based on ejection fraction?
- Heart failure with reduced ejection fraction (HFrEF)
- Heart failure with preserved ejection fraction (HFpEF)
HFrEF indicates ineffective contraction, while HFpEF indicates normal contraction but impaired relaxation.
What does preload refer to in the context of heart function?
Pressure on the myocardium when the heart is relaxed
It depends on systemic venous return.
What is afterload?
The force against which the ventricle must eject blood
Increased afterload requires greater contraction force and increases oxygen demand.
How is compensated heart failure different from decompensated heart failure?
Compensated heart failure has maintained cardiac output; decompensated has decreased stroke volume and edema
In decompensated heart failure, the body can no longer compensate for the decreased output.
What is the role of defibrillators?
To correct life-threatening heart rhythms by delivering an electric shock
It significantly improves survival rates in cases of ventricular fibrillation.
What is the incidence of cardiovascular disease (CVD) in New Zealand?
CVD incidence is significant and influenced by various risk factors.
Define ischaemic heart disease (IHD).
A condition characterized by reduced blood flow to the heart muscle.
What is hypertensive disease (HT)?
A condition related to high blood pressure affecting the cardiovascular system.
What is cerebrovascular disease (CBD)?
A disease that affects blood flow to the brain, potentially leading to stroke.
List the main risk factors for cardiovascular disease.
- Family history
- Gender
- Age
- Blood lipids
- Hypertension
- Cigarette smoking
- Obesity
- Lifestyle factors
- Diet
- Environmental exposure
What are lipoproteins?
Particles that transport cholesterol and triglycerides in the bloodstream.
Define hyperlipidaemias.
Abnormally high levels of lipids in the blood.
What does HDL stand for?
High-Density Lipoprotein.
What does LDL stand for?
Low-Density Lipoprotein.
What does VLDL stand for?
Very Low-Density Lipoprotein.
What role do plasma biomarkers play in diagnosing myocardial infarction?
They help identify heart muscle damage through protein levels in the blood.
True or False: Two-thirds of coronary deaths occur outside the hospital.
True.
What is arteriosclerosis?
A condition characterized by thickening and hardening of the arterial walls.
What is thrombogenesis?
The process of blood clot formation.
Fill in the blank: The main source of blood cholesterol is produced in the _______.
[liver]
What are the key features of the Mediterranean diet?
- More wholegrains
- Increased fruit and vegetables
- Healthy fats like olive oil
- Lean proteins
- Low fat dairy
What is the BMI range for obesity?
> 30
What does the Barker hypothesis suggest?
Prenatal influences can lead to increased risk of cardiovascular disease in adulthood.
List three cardiac biomarkers used to diagnose myocardial infarction.
- Troponin T (TnT)
- Creatine Kinase - CKMB
- Myoglobin
What effect does smoking have on cardiovascular health?
It reduces oxygen delivery and causes vasoconstriction.
What is metabolic syndrome?
A cluster of conditions that increase the risk of heart disease, stroke, and diabetes.
What is the purpose of anti-platelet medications?
To reduce the risk of blood clots.
What is the role of statins?
To reduce cholesterol production in the body.
True or False: Dietary interventions should focus solely on reducing cholesterol intake.
False.
What is the importance of public education in cardiovascular disease prevention?
It raises awareness and promotes early intervention.
What is a common characteristic of a blood cholesterol-lowering diet?
Focus on reducing saturated fats and increasing fiber intake.
Fill in the blank: An elevated ratio of _______ cholesterol to total cholesterol is protective against coronary heart disease.
[HDL]
What lifestyle change is recommended to manage body weight?
Sustained healthy eating and regular exercise.
What is CK-MB?
A heart-specific enzyme used in diagnosing myocardial infarction.
What is the role of folate in cardiovascular health?
It is a protective component in diets that may reduce cardiovascular risk.
What type of fat is considered healthy and is included in heart-healthy diets?
Monounsaturated fats, such as those found in olive oil.
What is the primary purpose of a 12-lead ECG?
To record 12 different views of the heart and provide a complete picture of the electrical activity.
What are the components of the conduction system of the heart?
- Sinoatrial (SA) node
- Internodal pathways
- Atrioventricular (AV) node
- Bundle of His
- Bundle branches
- Purkinje fibres
What defines a normal P wave in an ECG?
Atrial depolarization.
What does the QRS complex represent in an ECG?
Ventricular depolarization.
What does the T wave indicate in an ECG?
Ventricular repolarization.
What is the normal duration of the P wave?
0.11 s.
What is the normal range for the PR interval?
0.12 to 0.20 s.
What is the significance of the ST segment in an ECG?
It can indicate myocardial infarction or ischemia.
What is bradycardia defined as in terms of beats per minute?
<60 bpm.
What are some causes of bradycardia?
- Increased vagal tone
- Low body temperature
- Beta blockers
- Aerobic fitness
- Hypothyroidism
- Late hypoxia
- Severe intracranial hypertension
- SA node alterations
What defines tachycardia in beats per minute?
> 100 bpm.
What are some causes of tachycardia?
- Hypovolaemia
- Hyperthyroidism
- Adrenergic stimulation
- Elevated body temperature
- Vagalytic drugs
- Vasodilator drugs
What is the appearance of atrial flutter on an ECG?
Saw-tooth appearance with f waves.
What characterizes atrial fibrillation on an ECG?
Unsynchronized impulses from multiple ectopic foci, irregular baseline, and no visible P wave.
What is ventricular tachycardia?
Rapid premature ventricular contractions (>100 bpm) from an ectopic site or circuit.
What is the consequence of ventricular fibrillation?
No cardiac output and progression to cardiac arrest.
What is a first-degree block in ECG interpretation?
Slowed electrical impulse propagation between atria and ventricles.
What is a second-degree block?
Sometimes the atrial depolarization does not elicit ventricular depolarization (non-conducted P wave).
What occurs in a third-degree block?
The SA node signals are not transmitted to the ventricles; atria and ventricles have separate rhythms.
What is the normal duration range for the QRS complex?
Under 0.10 s.
What is the normal QT interval duration range?
0.35 to 0.44 s.
Fill in the blank: The method for determining the atrial rate using a 6-second strip is to multiply the number of P waves by _______.
10.
What is the significance of the cardiac axis in ECG interpretation?
Determines direction of ventricular depolarization based on positive/negative and equiphasic waves.
What does an irregular ventricular rhythm suggest in atrial flutter?
It may indicate a block or refractory period.
True or False: Atrial fibrillation has a regular ventricular rhythm.
False.
Define the term shock.
Any condition when blood vessels are not filled and blood cannot circulate normally. There is inadequate blood flow to meet tissue needs.
May result in cell and tissue death, and ultimately organ damage.
List the types of shock.
- Hypovolemic shock
- Vascular shock
- Cardiogenic shock
- Obstructive shock
- Transient vascular shock
Each type has distinct causes and symptoms.
What causes hypovolemic shock?
Rapid drop in blood volume due to:
* Large loss of blood (internal and/or externally)
* Severe vomiting or diarrhoea
* Significant burns
* Severe dehydration
Appears after a 30% loss in blood volume.
What are the symptoms of hypovolemic shock?
- Tachycardia
- Weak pulse
- Intense vasoconstriction
These symptoms result from the body’s response to decreased blood volume.
What characterizes vascular shock?
Normal blood volume, but poor circulation due to extreme vasodilation and falling BP.
Potential causes include anaphylactic shock, neurogenic shock, and septic shock.
What is cardiogenic shock?
Occurs when the heart pumps blood insufficiently, normally due to myocardial infarction.
This type of shock is critical and needs immediate medical attention.
What is obstructive shock?
Circulatory obstruction to blood flow, such as pulmonary embolism.
This type can lead to severe complications if not addressed promptly.
What is transient vascular shock?
Pooling of blood in lower extremities, poor venous return, and low BP, which can result in syncope (fainting).
It is usually temporary but can indicate underlying issues.
What are the symptoms of shock?
- Hypotension (systolic < 90mmHg)
- Pale, cool, clammy skin
- Confusion and disorientation
- Increased heart rate
- Decreased urination
- Acidosis
- Possible nausea
Symptoms can vary based on the type of shock present.
What characterizes the compensated stage of shock?
Homeostatic adjustments (short and long term).
This is the first stage where the body attempts to compensate for blood loss.
What happens in the progressive stage of shock?
Blood volume decreases >35%, decreased cardiac output, tissue damage, acidosis, clotting in blood vessels, myocardial damage.
This stage indicates severe physiological stress on the body.
What occurs during the irreversible stage of shock?
Rapid deterioration, death imminent, vasodilation, and fatal decline in blood pressure leading to circulatory collapse.
This is the final stage where recovery is unlikely.
What are the learning outcomes of the cardiac abnormalities lecture?
- Describe the development of the heart and great vessels
- Explain how this development is related to the changes between foetal and neonatal circulation
- Define the terms cyanotic and acyanotic
- Explain with examples why a congenital heart defect may be cyanotic or acyanotic
The learning outcomes provide a framework for understanding key concepts in cardiac abnormalities.
What is the key difference between foetal and neonatal circulation?
In foetal circulation, the right side of the heart has a higher pressure than the left, while in neonatal circulation, the left side has a higher pressure than the right.
This difference is crucial for the proper transition from foetal to neonatal life.
Define cyanotic congenital heart defects.
Cyanotic abnormalities are when deoxygenated blood enters the systemic circulation.
This can lead to lower oxygen levels in the blood.
Define acyanotic congenital heart defects.
Acyanotic abnormalities are when oxygenation of the systemic circulation is relatively normal.
Some oxygenated blood may re-enter the pulmonary circulation.
What are some examples of acyanotic abnormalities?
- Ventricular septal defects (VSDs)
- Atrial septal defects (ASDs)
- Aortic stenosis
- Coarctation of the Aorta
These conditions typically do not lead to significant oxygen deprivation.
What are some examples of cyanotic abnormalities?
- Tetralogy of Fallot
- Transposition of the Great Vessels
These conditions result in deoxygenated blood being circulated to the body.
What is a ventricular septal defect (VSD)?
A VSD occurs when the superior part of the interventricular septum fails to form, allowing blood to flow from the left ventricle to the right ventricle.
This defect occurs in about 1 in 500 births.
What characterizes an atrial septal defect (ASD)?
Most ASDs involve the foramen ovale being too large or the septum primum being too short.
This condition is classified as acyanotic.
What is patent ductus arteriosus?
It is a condition where blood flows from the higher pressure aorta to the lower pressure pulmonary artery, reducing systemic circulation.
This condition is more common in females and accounts for about 12% of all heart defects.
What is coarctation of the aorta?
It is the narrowing of the aorta near the ductus arteriosus, which can lead to collateral circulation.
This defect occurs in about 6% of heart defects and is three times more common in males.
What are the four defects that make up Tetralogy of Fallot?
- Ventricular septal defect
- Pulmonary stenosis
- Overriding aorta
- Right ventricular hypertrophy
This condition leads to decreased blood flow to the lungs and mixing of oxygenated and deoxygenated blood.
What happens during the failure of the truncus arteriosus to spiral?
It results in transposition of the great vessels, where the aorta arises from the right side and the pulmonary artery from the left side of the heart.
Survival requires some form of septal defect or a patent ductus arteriosus.
What are the effects of a stenotic aortic valve?
It makes it more difficult for blood to flow into the aorta, causing increased left ventricular pressure and hypertrophy.
The left ventricle compensates by contracting harder.
What is a leaky aortic valve?
It is a faulty valve that allows blood to flow back into the ventricle during diastole, causing a murmur.
This can be detected as an additional sound during the cardiac cycle.
What occurs with mitral valve stenosis?
It makes it more difficult for blood to flow to the left ventricle, leading to increased left atrial pressure and hypertrophy of the left atrium.
The left atrium compensates through increased contraction.
What are genetic determinants of Tetralogy of Fallot?
Mutations in genes like GATA-4 or GATA-6 have been associated with this condition.
GATA-binding proteins control gene expression and differentiation in various cell types.
What is the significance of the foramen ovale in foetal circulation?
It allows oxygenated foetal blood to flow from the right atrium to the left atrium due to higher pressure in the right side.
This structure is crucial for proper blood flow during foetal development.
Fill in the blank: A ventricular septal defect (VSD) is a condition where a hole is present between the _______ and _______.
[right ventricle] and [left ventricle]
Aldosterone acts to raise blood pressure andits production is stimulated by…?
1. Lower levels of growth hormone
2. Increasing levels of plasma angiotensin 2
3. Low plasma potassium levels
4. Raised level of adrenaline
Increaseing levels of plasma angiotensin 2
Hypertension is defined as?
1. Systolic >140mmHg and diastolic >90mmHg
2. Blood pressure too low to measure
3. Systolic <100mmHg or diastolic <60mmHg
4. Systolic >140mmHg or diastolic >90mmHg
Systolic >140mmHg
OR
Diastolic >90mmHg
Symptoms of angina occure ususally when a person…?
1. is exercising
2. has taken vasodilators
3. is at rest
4. has taken aspirin
Is exercising
A protective factor reducing the risk of human coronary heart disease is…?
1. Slightly low blood pressure
2. Drinking three cups of tea per day
3. An elevated ratio of LDL cholesterol : total cholesterol in the bloodstream
4. An elevated ratio of HDL cholesterol : total cholesterol in the bloodstream
- An elevated ratio of HDL cholesterol : total cholesterol in the bloodstream
A non-ST-elevation myocardial infarction is most conclusively detected by…?
1. Measuring cardiac biomarkers from a blood sample
2. Echocardiography
3. Angioplasty
4. Electrocardiogram
- Measuring cardiac biomarkers from a blood sample
Bradycardia is defined as a heart rate of…?
1. Greater than 100 bpm
2. Greater than 25 bpm
3. 75 bpm
4. Less than 60 bpm
Less than 60 bpm
An ECG trace with T wave inversion suggests?
1. Tetralogy of Fallot
2. Ectopic foci firing
3. cardiac ischaemia
4. Ventricular fibrillation
- Cardiac ischaemia
A definition of shock is…?
1. Blood vessles are not filled and blood cannot circulate normally
2. Receiving a major fright
3. Short hiatus of cardiac kinesis
4. Stunning of the heart so that it stops beating
- Blood vessels are not filled and blood cannot circulate normally
Cardiogenic shock occurs when…?
1. The heart has faulty genes
2. There is a shunt beetween teh aorta and the pulmonary artery
3. The heart pumps blood insufficiently
4. The left ventricle of the heart is enlarged
The heart pumps blood insufficiently
Acyanotic cardiac abnormalities occur when…?
1. A baby has copper poisoning
2. Oxygenation of the systemic circulation is relatively normal
3. Cyanide binds to haemoglobin in red blood cels
4. The major blood vessels entering and leaving the heart are transposed
. Oxygenation of the systemic circulation is relatively normal
Two examples of acyanotic cardiac abnormalities are…?
1. Atrial septal defect & Aortic stenosis
2. Pericarditis & Periodontitis
3. Abdominal aortic aneurysm & Algesia
4. Tetralogy of Fallot & Transportation of the great vessels
Atrial septal defect & aortic stenosis
