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).