The Clinical Study Of The Cardiac Function Of Patients With Chronic Heart Failure Treated By Carvedilol

Background:CHF is a commonly-found complicated clinical synd- rome which is due to all kinds of myocardial cell injuries causing heart remodeling,worsening cardiac function and leading to low LVEF finally. With the development of molecular biology of heart, the mechanism of HF is deeply researched, as a result, the importance of the activation of RAS in the occurrence and development of HF is recognized. Among many relevant drugs,β-receptor blockers , which can lower the heart rate and blood pressure, decrease heart oxygen consumption, prevent injuries from CA , reverse the heart remodeling and improve the cardiac function by blocking adrenoceptors have drawn more and more concentration.β- receptor blockers can be defined into 3 generations: the frist generation is non-selective and represented by propranolol which can block bothβ1-receptors andβ2-receptors and is rarely administered because of serious side effects;the second generation is highly selective and represented by metoprolol and bisoprolol both of which can only blockβ1-receptors, restrain the systole of heart, lower the heart rate and the blood pressure and is commonly used to treat hypertension and arrhy- thmia etc. However they can cause severe HF in patients with heart block, although their positive effects on cardiac function and mortality were proved by many big clinical trials; the third generation is non-selective and represented by carvedilol, which can strengthen the reaction of myocardial cells, improve the systole of heart, and relax the vessels by blocking bothβ-receptors andα1-receptors. And it can also reverse the heart remod- eling by resisting oxidative stress and improving the survival of the myoc- ardial cells. Carvedilol has become the focus of clinical trials over the world attributed to reasons stated above. Nevertheless, there has not been so many trials concentrating on evaluating cardiac function with the use of both color ultrasound and BioZ.com system and investigating the effects of carvedilol on CHF patients with rapid arrhythmia.Objective: 57 CHF patients with rapid arrhythmia were strictly chosen from January 2008 to March 2009. They were divided into the carvedilol group and the control group randomly, treated by carvedilol and routine therapy( diuretics and digitalis preparations etc. were administered), survey and record systolic pressure, heart rate, LVEF, LVEDD, E/A, SV, rapid arrhythmia etc. to investigate the short-term effect and long-term effect of carvedilol on blood pressure, heart rate, heart structure, cardiac function and rapid arrhythmia.Method: The carvedilol group were given carvedilol from a dose of 3.125mg, PO, bid for 14 days on the basis of routine therapy. If without heart block and lowered heart rate, the dose would be increased to 6.25mg, PO, bid, and be increased every 7-14days without severe side effects until the maximum recommended(25mg if weight <80kg, 50mg if weight>80kg) or the maximum tolerated(blood pressure<100/70mmHg, heart rate<60bpm or dizziness, impuissance etc. occur) were reached. The maximum would be maintained until the whole therapy lasted 6 months. The control group just received the routine therapy during the whole process. The factors to be observed were listed as below: (1)basic factors: systolic pressure, heart rate and both evaluated 3 times per day( at 6 am, 2pm, 10pm) and then the average selected for applying statistics; (2) factors measured by color ultrasound: LVEF, LVEDD, E/A, IVRT; (3) factors measured by BioZ system: SV, ACI, SVR, TFC; (4) the number of patients with sorts of rapid arrhythmia depended on Zymed-8180; (5) the class of cardiac function depends on evaluation based on standards of NYHA. Every one week, the blood pressure, heart rate were measure, the administration of drugs, the activaty ability, the HF syndrome and the condition of survival were observed. If without severe side effects, increase the dose of carvedilol. All the factors listed above will be measured and the cardiac function will be evaluated after 14 days and 6 months. Standard applied: for cardiac function: very effective: the class of the cardiac function improved by more than 2 classed or classⅡreached, effective: the class of the cardiac function improved by more than 1 class, not effective: the class of the cardiac function improved by no more than 1 class; For rapid arrhythmia, very effective: nodal tachycardia completely recovered, the heart rate of patients with rapid auricular fibrillation controlled under 100bpm, the number of auriculars extra systoles or ventricular extra systoles of patients decreased by more than 90%; effective: the number of auriculars extra systoles or ventricular extra systoles of patients decreased by more than 75%; not effective: nodal tachycardia remained or rapid auricular fibrillation remained, the number of auriculars extra systoles or ventricular extra systoles of patients decreased by no more than 75%. All the values are demonstrated as x±s and analyzed with statistical software CS10.34. The comparison between two groups was applied with grouped t test and the comparison of the carvedilol group between before and after treatment was applied with coupled t test. The difference is meaningful when P<0.05.Results: (1)basic factors: after 14 days, compared with the value before 14 days and the value of the control group, the average of the heart rate of the carvedilol group was decreased significantly from 103bpm to 92bpm (P<0.05), compared with the value before 14 days and the value of the control group, the average of the systolic pressure of the carvedilol group was decreased significantly from 145mmHg to 130mmHg(P<0.05); after 6 months, the heart rate of the carvedilol group continued to decrease to 65±5bmp and the systolic pressure continued to decrease to 122±16mmHg. (2) factors reflecting the structure and the function of the heart: after 14 days, LVEF, E/A, SV, LVEDD etc. of the carvedilol group were similar to those of the control group; after 6 months , compared with values before 6 months and the values of the control group after 6 months, the average of LVEF of the carvedilol group was increased significantly from 35.99% to 45.67%(P<0.05) and the average of E/A of the carvedilol group was increased significantly from 0.59 to 0.91(P<0.05) and the average of SV of the carvedilol group was increased from 73.05ml to 79.10ml( P<0.05). (3) rapid arrhythmia: carvedilol can improve rapid arrhythmia of the patients in a short term and the total effective rate reached 83.87%; its function remained in a long term and the total effective rate reached 90.32%. (4) the class of the cardiac function: based on the NYHA standard, the cardiac function did not improve so much before and after 14 days(P>0.05); however, after 6 months, compared with the value before treatment and the value of the control group, the class of the cardiac function of the carvedilol group improved significantly(P<0.05); in the carvedilol group, the number of patients with classⅣwas decreased from 2 to none and the number of patients with classⅢwas decreased from 10 to 4,and the syndromes such as dyspnea of the patients with classⅡwere improved; the average of the class of the card- iac function was decreased from 2.45 to 2.13.Conclusion: 1. Carvedilol can decrease the heart rate and the systolic pressure in a short term and this effect will remain in a long term and improve syndromes like dyspnea, inability etc.; 2. carvedilol can increase LVEF, SV, E/A, and decrease LVEDD and so it can reverse the heart remodeling and improve the cardiac function; 3. carvedilol can improve the rapid arrhythmia of the patients in a short term and the effect remains in a long term; 4. carvedilol can improve the class of the cardiac function of the patients in a long term.