Category Archives: Cardiovascular disease

Variations in blood pressure

The systolic blood pressure varies by up to 10 mmHg between the right and left brachial arteries. Standing usually causes a slight reduction of the systolic pressure «20 mmHg) and an increase in the diastolic blood pressure «10 mmHg). In postural (orthostatic) hypotension, a large postural fall of both the systolic and diastolic pressures is associated with dizziness. When anirregular heart rhythm such as at

Examination of the cardiovascular system

GENERAL EXAMINATION General features of the patient’s well-being should be noted as well as the presence of anaemia, obesity, jaundice and cachexia . Clubbing  The most common cardiac causes of severe clubbing are subacute infective endocarditis and congenital cyanotic heart disease, particularly Fallot’s tetralogy. Clubbing takes many months to develop and is therefore not seen in acute endocard

Paroxysmal nocturnal dyspnoea (PNO)

This occurs when there is an accumulation of fluid in the lungs (pulmonary oedema) at night. The mechanism is similar to orthopnoea, but because sensory awareness is depressed during sleep, severe interstitial and alveolar oedema can accumulate. The patient is woken from sleep fighting for breath, a dramatic and frightening experience. The breathlessness may be relieved by sitting on the side of the bed or g

Symptoms of heart disease

Patients even with severe heart disease may be asymptomatic. However, symptoms include the following. Pressure-volume loop. Dyspnoea Dyspnoea is an awareness of breathlessness. It can be due to cardiac or respiratory causes. It is also a symptom during exercise in healthy people. Breathlessness may occur only on exercise or may be present at rest. The New York Heart Association has replaced by a very similar

The law of Laplace

This is also relevant to the contractile function of the heart. Laplace stated that the pressure within a sphere is proportional to wall stress (in the heart this is equivalent to after-load) and inversely proportional to its radius. Thus, as the heart enlarges beyond the point at which Starling’s law conferred an advantage, the wall stress increases and cardiac output falls. The conduction system of t

Essential anatomy, physiology and embryology of the heart

The cellular basis of myocardial contraction Myocardial cells contain bundles of parallel myofibrils. Each myofibril is made up of a series of sarcomeres A sarcomere is bound by two transverse Z lines, to each of which is attached a perpendicular filament of the protein actin. The actin filaments from each of the two Z bands overlap with thicker parallel protein filaments known as myosin. Actin and myosin f

Cardiovascular disease

Introduction In the Western Hemisphere approximately 50% of deaths are related to cardiovascular disease. This is due mainly to ischaemic heart disease that could, perhaps, be significantly reduced if smoking were prohibited, life-style moderated (e.g. weight reduction) and the intake of cholesterol and saturated fats reduced. Whilst the incidence of rheumatic heart disease is decreasing in the West, it is s