CV Diseases/ Malfunctions Flashcards
What is Fibrillation?
Irregular and rapid contraction of a muscle fibre. Can be due to fibres loosing contact with innervating axons, motor neurone lesions or electrolyte imbalances
What is the cause of fixed mottling of a dead leg (acute limb ischemia)?
When a major artery to the leg is blocked (thrombosis, trauma ect), so tissues start to die. This happens more in leg as less collateral blood flow. Cells then start to die (necrosis) and the limb will appear blue.
What is treatment for fixed mottling of dead leg? Why is this done?
Amputation- dead cells will start to release toxic Ca2+ (Hypercalcemia) or K+ (Hyperkalacemia)
High K+ can lead to heart attack as it interferes with electrical conductance in the heart
What is cardiac hypertension, its cause and result?
Where muscle cells in L. Ventricle sweet (hypertrophy).
Due to increased blood pressure, valve stenosis (blockage), CHD ect
Leads to smaller stroke volume and so increasing risk of heart failure.
What is ventricular distension? What causes it?
When the myosin filaments are over stretched and so no longer attached to actin filaments and so the sarcomere breaks. This means the ventricular contraction is not as strong.
It is caused by damadge to muscle, congenital defects, faulty valves, high blood pressure, arrhythmias
What is paroxysmal nocturnal dyspnoa?
Extreme shortness of breath at night because of pulmonary oedema. This is caused by malfunctioning L. Ventricle causing higher venous blood pressure at the lungs and when you lie down the pressure in the veins at the lungs becomes even greater (no gravity) and so oedema forms
What is orthopnoea?
Shortness of breath from lying flat
What two natriuretic peptides are a marker for ventricular distension?
BNP and ANP.
Both are released to try and decrease blood volume and so reduce blood pressure
What is heart failure and what are the signs
Heart unable to pump properly
- shortness of breath (dyspnea)
- fatigue and weakness
- coughing up pink foamy mucus
- oedema in legs ankles and feet
- Swelling in abdomen (ascites)
- weight gain from water retention
- lack of appetite and nausia
- chest pain if cause of heart failure is heart attack
What could cause heart failure?
Distension Hypertorphy of ventricle Myocardial infarction Arrhythmias Congenital diseases CHD Damage to valves
Which artery is blocked if the problem is electrical in heart.
Right coronary artery
Which coronary artery is blocked if there is myocardial infarction?
Left
What two enzymes mark a myocardial infarction
Creatine kinase and cardiac troponin 1
What is frank- starlings law? What are the two axis and how does graph change in CHD ?
The idea that there is optimal ventricular filling for maximum intropy.
X= ventricle filling. Y= stroke volume
Peak gets lower down the more severe the CHD
