Arrhythmia caused by abnormal function of the mechanical heart

These arrhythmias can be divided into two groups. The first group includes sinus tachycardia, sinus bradycardia and sinus arrhythmia in which the starting point for the heart to contract remains sinus node - homotopy rhythm; the only change is the number or sequence of outgoing from node pulses. The second group consists of atrioventricular rhythm, migration source of a heart rhythm, interfering dissociation, termination atrial contractions, idioventricular rhythm in which steadfastly or temporarily change the starting point of excitation of the heart and the source of rhythm instead of the sinus node becomes any other point conductive system of the heart - heterotopic rhythm. This is usually changed and heart rate.
Sinus tachycardia is characterized by the increased frequency of rhythmic heartbeat (over 100 In 1 min). It may be caused by emotions, physical exertion, fever, thyrotoxicosis, anemia, heart failure, the effects of the drugs (atropine, ephedrine, caffeine, nitrites and other).
The clinical picture. Typical complaint sick at heart. The number of heartbeats usually 120 - 160, in rare cases can reach up to 180 to 200 beats per 1 min. of the Neck veins are usually too deep. The first tone at the top is often reinforced; pulmonary artery sometimes you can hear systolic murmur. ECG (Fig. 1) the form of atrial and ventricular complexes not changed. Due to the shortening of diastole sharply reduced the interval T - R. When the heart rate over 150 prong R can be merged with the previous wave So the Diagnosis is usually not difficult. The treatment includes effect on the disease process causing the increase of heart.

sinus tachycardia
Fig. 1. Sinus tachycardia.

Sinus bradycardia is to decrease heart rate (less than 60 beats per 1 min). May be due to: direct and reflex stimulation of the cortex of the brain tumors and brain injury; increased intracranial pressure; enhanced action on the heart parasympathetic nervous system; low impact on the heart of the sympathetic; the defeat of the sinus node in the result of direct or reflex exposure to various endogenous and exogenous factors. There is sometimes in healthy athletes and those engaged in heavy physical labour.
The clinical picture. The number of heartbeats ranges from 40 to 60, rarely less than 40 beats per 1 min. Border heart with percussion and x-ray examination is usually normal. Heart sounds clean or deaf. ECG (Fig. 2) the form of atrial and ventricular complexes not changed. The interval P - Q slightly increased. Cut Q - T increases with the decrease in the number of heart contractions.

sinus bradycardia
Fig. 2. Sinus bradycardia. SFG - spirogramma brachial artery.

The diagnosis is usually difficulties is not. When sinus b for CT divas, unlike bradycardia when AV blockade (see below), the power of the first tone at all abbreviations are the same.
Treatment is not usually required. If necessary, designate atropine. Sinus bradycardia itself reduce disability is.
Sinus arrhythmia is changing the size of the intervals between heartbeats.
In most cases, sinus arrhythmia associated with the act of breathing - respiratory arrhythmia. The number of heart rate increases when you inhale and decreases when you exhale. Respiratory arrhythmia is often observed in healthy people in childhood and young age, less frequently in adults and the elderly.
Sinus arrhythmia, not associated with the act of breathing, sometimes observed in acute myocarditis due to damage to the sinus node, with long-term treatment with digitalis and occasionally in the agonal period.
The clinical picture. Subjective sensations and circulatory disorders are missing. ECG form of atrial and ventricular complexes almost no changes; varies only the interval T - R (Fig. 3).

sinus (respiratory) arrhythmia
Fig. 3. Sinus (respiratory) arrhythmia. PG - pneumogram.

The diagnosis may be established by feeling the pulse and listening. Proof that sinus arrhythmia is breathing, is the disappearance of arrhythmia with breath. Respiratory sinus arrhythmia on work capacity is not affected and does not require treatment.
Treatment and ability to work with sinus arrhythmia, not associated with the act of breathing, defined caused her illness.
Of atrioventricular (nodal) rhythm. The driver of a heart rhythm is not sinoatrial node (automatic centre of the first order), and the atrioventricular node (automatic centre of the second order). When the atrioventricular rhythm starting point of occurrence automatic pulse can be either upper part of atrioventricular node, located in the Atria, or average, located on the border of the Atria and ventricles, or lower - ventricular the host part.
The origin of automatic pulse is localized sometimes in the area of the mouth of the coronary sinus heart and substrate branching coming from the upper part of atrioventricular node - rhythm of the coronary sinus - coronary sinus [Tsang (W. Zahn)]. Excitation fibrillation always happens retrograde way. The main reason for the persistent occurrence of atrioventricular rhythm is, apparently, the defeat of the sinus node.
Has a certain value and condition of the Central nervous system (cerebral cortex and autonomic centers). Cases of persistent of atrioventricular rhythm are rare. The number of heartbeats in the atrioventricular rhythm depends on the localization of the source point automatic pulse in the atrioventricular node.
The clinical picture. The impact of this type of arrhythmia on the heart is not so great. Complaints of patients minor, sometimes they are concerned about the surge in the neck. When viewed clearly visible ripple neck veins, almost in sync with the pulse of the radial artery. The number of heartbeats ranges from 80 (in the localization automatic pulse in the upper part of atrioventricular node) to 40 in 1 minute (in the localization automatic pulse in the lower part of atrioventricular node). Under fluoroscopy enhanced visible ripple top Vena cava.

atrioventricular rhythm
Fig. 4. Atrioventricular rhythm coming from the top of the site. SFG brachial artery.


ECG negative, and P wave is localized, depending on the place of origin of automatic pulse or ahead of the QRS complex (Fig. 4), or overlapped with the QRS complex, or is between the micro and the T wave (Fig. 5)When starting point of occurrence automatic pulse is localized in the upper branches of atrioventricular node, in the coronary sinus (rhythm coronary sinus), prong R precedes the QRS complex. In lead it is positive, and in the II and III leads negative. In breast and unipolar leads from limbs form, and P wave is the same as in the localization automatic pulse at the top of the site (Fig. 6). For FCG characterized by the absence of atrial oscillations first tone.

atrioventricular rhythm coming from the bottom of the site
Fig. 5. Atrioventricular rhythm coming from the bottom of the site.
the rhythm of the coronary sinus coronary sinus
Fig. 6. The rhythm of the coronary sinus coronary sinus. ECG standard, thoracic and unipolar from limb leads.

The diagnosis can only be made on the basis of data electrocardiographic studies. Ability to work with this type of arrhythmia is determined by the nature of the lesion of the heart and circulation.
Treatment of atrioventricular rhythm little successfully. Sometimes the impact of the car - or simpatikotonia funds temporarily restore sinus rhythm.
Interfering dissociation - rhythm disturbances, involving simultaneous existence of two sources of heart rhythm in the sinoatrial and atrioventricular nodes, and the emergence of automatic pulse in the atrioventricular node occurs with greater frequency than in the sinus. Interfering dissociation is caused in most cases by the defeat of the sinus node and decrease of a number from the automatic pulse. By lowering the automaticity of sinus node begins the automatic atrioventricular node. Interfering dissociation occurs during treatment with digitalis and for infectious diseases, especially in acute rheumatism, being an indication of myocarditis.
Clinical presentation is determined by the primary disease. ECG along with the normal associate reductions of the Atria and ventricles are observed independent of each other atrial contraction coming from the sinus node, and reduction of the ventricles emanating from the atrioventricular node (Fig. 7).

interfering dissociation
Fig. 7. Interfering dissociation. SFG brachial artery.

The diagnosis is established on the basis of data electrocardiographic studies.
Treatment and ability to work depends on the underlying disease.
Idioventricular rhythm observed in cases where the origin of the occurrence of an automatic pulse heart becomes some point wiring system, located below the atrioventricular node, i.e. automatic centre of the third order is the bundle of his - or its fork. In this case the excitation fibrillation often happens retrograde way.
ECG form QRs complex depends on the starting point of occurrence automatic pulse; when localizing a starting point below dividing the bundle of his legs form QRs complex changed.
The diagnosis is established on the basis of ECG examination.
Treatment and ability to work are defined by the disease that caused idioventricular rhythm.