Table of contents:

Table of contents:

• Properties of the myocardium • Electrocardiogram: general aspects • Pathophysiology of atrial and ventricular overload • Pathophysiology of driving disorders • Pathophysiology of rhythm disorders • Pathophysiology of cardiac perfusion disorders • Heart exploration methods • Exploring the vascular system • Methods of functional exploration of the respiratory system - spirometry • References • ANNEX 1 - Elecetrocariograms • ANNEX 2 - Spirometries • ANNEX 3 - ECG interpretation

Fragment din cartea "Pathophysiology Cardiovascular and Respiratory Systems" de Alexandra Floriana Nemes, Andreea Plesa, Nemes Roxana Maria, Plesa Florentina Cristina:

Chapter V Pathophysiology of rhythm disorders Overview Normally, at rest, the heart rhythm is regular, with a heart rate of 60-100 beats/minute and is determined by depolarization of the sinus node :SN) = normal sinus rhythm

- any change in the normal sinus rhythm is called arrhythmia/ dysrhythmia and occurs through:

• the origin of the driving impulse outside the SN;

• rhythm disturbance;

• frequency change;

• impulse conduction impairment.

- arrhythmias can be: paroxysmal; sustained.

Arrhythmia can be asymptomatic or with various clinical manifestations such as:

• palpitations with an accelerated or slowed rhythm, regular or irregular, accompanied by unpleasant sensations or even a feeling of imminent death

• dizziness or short-term loss of consciousness (syncope) due to low cardiac output

• chest pain, angina especially in the case of fast-paced arrhythmias that increase oxygen demand over intake (often associated with coronary artery disease) • signs of decompensated heart failure or even sudden death in the event of an acute myocardial infarction or life-threatening arrhythmias

Arrhythmogenic factors - very important to identify, so that you can treat them D. drugs la ischemia S. sympathotonus H. hypoxia E. electrolitic disturbances S. stretch

Investigation of arrhythmias

• ECG- the best investigation for the diagnosis of cardiac arrhythmias;

• rhythm strips- longer routes on one or more derivations (choose the most eloquent derivation);

• Holter ECG over 24-48 hours or up to 2 weeks and recording symptoms in a diary to correlate with the ECG recording;

• ambulatory monitor which registers a derivation, usually precordial;

• event monitor which records about 5 minutes at the request of the patient when he has symptoms; can be implanted subcutaneously for a longer period (one year).