Room tachycardia _ general knowledge that the ischemic myocardium disease patient takes place

Room tachycardia _ general knowledge that the ischemic myocardium disease patient takes place
Room tachycardia which is short of blood myocardium disease
The room arrhythmia is the main reason that the disease patient of coronary artery dies suddenly. It is may for cardiac muscle ischemic in arrhythmia acute to behave one kinds,or before infarction and last cicatrix to cause. Stop up the coronary artery in early days, because the activation of ATP sensitive potassium passway and flux of potassium ion lead to the fact some movement electric potential time course is shortened, thereupon calcium overloads in cells, some acidosis and connecting the albumen ( Cx 43) Take off phosphorylation, enable the uniting and reducing occasionally of cells. The some change conduct in depolarization, it enables to be much shape room tachycardia (VT) Often develop into the ventricle and quiver (VF) . When ischemic progress reaches infarction, the cardiac muscle surviving is replaced by fibrous cicatrix. The cicatrix tissue will survive the cardiac muscle will be separated, especially in the edge zone of infarction, have offered the foundation for emergence of lasting room tachycardia after infarction. After the acute cardiac muscle is damaged and repaired, heart function and state are changed to some extent. Because the infarction district does not shrink the extension organizing and the area is expanded, not loose in the infarction district, the infarction district still metabolizes actively at the same time, companion's collagenic constant deposition and changing the sex. Until constant fiber of cardiac muscle take and ventricle expand, heart take place progressively structure reinvent, it makes the cardiac muscle present the arrhythmia more easily that electrochemistry after damaging at the same time is reconstructed. Except the change of the structure, the electricity reconstructs the abnormal state including abnormal state and sodium potassium electric current that myocardium cell calcium circulates. Because the activation of humoral factor of nerve that sympathetic nerve excitement, electrolytic disorder and fiber cause further promotes the arrhythmia to take place.
With the deterioration of the ventricle function, room dangerous increase with not normal rhythm of the heart. Cicatrix on it is big and among take quality fiber cell that be followed among solve to unite electricity occasionally, the arrhythmia appears more easily. Though pump function that the death reason of the later period in heart failure is mainly is depleted, but with the decline of the ventricle function, the room arrhythmia remains the main causes of death.
What patients need ICD?
It can be a passing single incident that the thrombus of acute coronary artery stops up much shape VT/VF caused, the danger of recuring is relatively low. Contrary to this, lasting VT/VF caused by chronic ventricle cicatrix, VT recuring rate exceeds 30% in following up a case by regular visits to 2, these patients usually need to plant into ICD.
Predict it is relatively difficult for the myocardium infarction patient without arrhythmia to the arrhythmia danger dying suddenly takes place. It is not an invading inspection means on the basis of finding and conducting slowing down, the depolarization changes or the sympathetic nerve is excited and is set up, because the limited its result of positive prediction accuracy is disappointing. In addition, the therapeutic method based on above-mentioned factor can't improve the prognosis effectively. Electric physiology (EP) in the heart Check, have high sensitiveness to single shape exploration of VT ' 90%) ,But predict the result of dying suddenly is limited. The incidence of the incident is 5%~7% every year that EP checks the negative serious LV function not complete patient. So, the ejection fraction of left ventricle (LVEF) at present The ones that are still accepted extensively die suddenly and predict the index. The serious left room function caused by coronary artery pathological change is not complete (LVEFlt; 30%) Patient, planting into ICD can reduce mortality. New image study means, can carry on dangerous to divide layer better, gadolinium, MRI of heart, strengthen, scan, can find the intersection of infarction and peripheral situation of area, predict the death is dangerous. Have data indicate it is easy for heredity not to contribute to dangerous to divide layer into while being perceptual constantly at the same time. Patient with family's history of dying suddenly, when raising myocardium infarction of section ST take place, the ventricle more incident quivers.
Prevent the arrhythmia from recuring
Once the patient plants into ICD, treat and concentrate on preventing VT from recuring. VT not merely influences the patient's life quality, and the dangerous sign that increases in heart failure that VT recurs or dies. Resisting the arrhythmia medicine can reduce the emergence of VT to ask for his Lip river or amine iodine ketone, but further use because of the limitations of toxicity of the medicine. It is of great importance that the conduit melts and treats in reducing VT to break out. Conduit mark examine to can visit, find normal sinus or get up incident the intersection of heart and the intersection of cicatrix and area of VT fight rhythm of the heart, while being regular to use system, situation when but can't ascertain VT. This makes the patient present dynamics of blood can accept VT melts when being unstable, do not need to lengthen the outbreak of inducing VT. The recent many centre tests of medicine difficult curing VT caused to ischemic myocardium disease show, patient accept the conduit melt VT breaks out from 11 treat, ' Median) Have reduced to 0. Though outbreak of VT reduce notably, about half the patient VT break out one day at least in not following up a case by regular visits to, point out and plant into the importance that ICD continues preventing from breaking out. The relevant case fatality rate is 3% that the conduit melts, usually because the operation fails to cause VT that can't be controlled to cause. Film is returned outside the membrane or heart in the anatomy obstacle such as heart that the film melts in the heart, operate the main reason to fail, but some of VT can be through examining the skill through the mark of membrane outside the leather heart, or the experienced centre melts through coronary artery alcohol the skill is solved under some situations. To constant VT or VT storm (VT storm) The patient will come to say, the conduit melts the skill can save the life.
Though does not still clear whether VT is that the ventricle function worsens the index, or ICD shock has negative effect on heart function, but VT and the intersection of prognosis and relevance among being bad brief on, prevent emergence of VT but prognosis of patient, ICD of improvement? VT patient ' Have not recured repeatedly) It is accepted that the random research of ICD treatment indicates, the conduit melts the skill can reduce 65% of the ICD shock, but because study sample quantity smaller, has not assessed its impact on mortality.
To the consideration in heart failure
Ischemic myocardium disease and pump depleted death and going on of VT patient are in heart failure and high and dangerous, cause people to the attention not completely therapeutic of heart function. In multiple clinical trials, receptor blocks pharmaceutical and renin - angiotensin - aldosterone system can reduce heart reconstructing, pump depleted death and arrhythmia that causes and die suddenly to resist pharmaceuticals short of moneyly. Which is short of blood myocardium disease patient VT emergence, might brief patient on heart failure, the intersection of cardiac muscle and ischemic or unusual electrolyte to have person who go on, indicate that needs to revitalize the plan of making a diagnosis. In some patients, VT may be the manifestation in later period of disease, unless the patient carries on the heart transplant or plants into the treatment that the ventricle supported to be equipped, ICD only plays a very small role in lengthening the life. In cases these are complicated, it is very important to listen to electric physiology and opinion of the professional doctor in heart failure.
Conclusion
In the ischemic myocardium disease patient, the room arrhythmia is the important reason to die suddenly, also the sign that the pump function worsens. Myocardium blood vessel rebuild skill, the intersection of and receptor, block pharmaceutical and renin - angiotensin - the intersection of aldosterone and system, it resists pharmaceuticals to be important treatment means to reduce mortality while being short of money. Person who plant into it defibrillates devices to be to prevent from main means that arrhythmia die suddenly, break out VT repeatedly, should revitalize and treat the plan, consider the skill of using the conduit to melt.
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