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Print version ISSN 0034-7094
Rev. Bras. Anestesiol. vol.54 no.2 Campinas Mar./Apr. 2004
Cardiac arrhythmias and ST changes in the perioperative period of elderly patients submitted to transurethral prostatectomy under spinal anesthesia. Comparative study*
Disritmias cardíacas y alteraciones del segmento ST en ancianos en el perioperatorio de resección transuretral de la próstata sobre raquianestesia. Estudio comparativo
Beatriz Lemos da Silva Mandim, TSA, M.D.I; Renato Enrique Sologuren Achá, M.D.II; Neuber Martins Fonseca, TSA, M.D.III; Fabiano Zumpano, M.D.IV
ICo-Responsável pelo CET/SBA;
Professora Substituta Mestre da Disciplina de Anestesiologia da UFU
IIProfessor Titular Doutor da Disciplina de Cardiologia da UFU
IIIResponsável pelo CET/SBA; Professor Adjunto Doutor da Disciplina de Anestesiologia da UFU
IVEx-ME2 do CET/SBA da UFU
BACKGROUND AND OBJECTIVES: Elderly account
for 25% of surgical patients. Several patients with arterial heart disease have
normal preoperative ECG and a high incidence of silent myocardial acute infarction
in the first postoperative week. Arrhythmias increase with age and supraventricular
and ventricular premature complexes, atrial fibrillation and intraventricular
conduction abnormalities are observed. This study aimed at evaluating the prevalence
of perioperative arrhythmias and ST changes through Holter System in elderly
patients submitted to transurethral prostatectomy and inguinal hernia repair
under spinal anesthesia.
METHODS: Participated in this study 21 patients aged 65 to 84 years submitted to transurethral prostatectomy (TUP) and 16 patients aged 63 to 86 years submitted to inguinal hernia repair under spinal anesthesia. Monitoring with Holter System was performed in the preoperative (12 hours), intraoperative (3 hours) and postoperative (12 hours) periods.
RESULTS: The prevalence of supraventricular premature complex was 85.7% vs. 93.7% in the preoperative period, 85.7% vs. 81.2% in the intraoperative and 76.2% vs. 100% in the postoperative period, respectively for groups TUP and control. The prevalence of ventricular premature complex was 76.2% vs. 81.2% in the preoperative period, 80.9% vs. 68.7% in the intraoperative period, and 80.9% vs. 81.2% in the postoperative period, respectively for groups TUP and control. The prevalence of ST changes was 19% vs. 18.7% in the preoperative period, 4.7% vs. 18.7% in the in the intraoperative period, and 14.3% vs. 18.7% in the postoperative period between groups TUP and control, without statistical significance.
CONCLUSIONS: Elderly patients have a high prevalence of supraventricular and ventricular cardiac arrhythmias. The total number of preoperative arrhythmias and ST changes was not changed as a function of transurethral prostatectomy surgery or inguinal hernia repair, in the intra and postoperative periods.
Key Words: ANESTHETIC TECHNIQUES, Regional: spinal block; COMPLICATIONS: cardiac arrhythmias; SURGERY, Urologic: prostatectomy
JUSTIFICATIVA Y OBJETIVOS: Ancianos representan
25% del total de los pacientes quirúrgicos. Muchos pacientes con enfermedad
arterial coronariana (DAC) presentan electrocardiograma (ECG) pre-operatorio
normal, y alta incidencia de infarto agudo del miocárdio (IAM) silencioso
en la 1ª semana de pos-operatorio. Las disritmias aumentan con la edad, siendo
observadas extrasístoles supraventriculares (ESSV) y ventriculares (ESV),
fibrilación atrial y disturbios de la conducción intraventricular.
El objetivo de este estudio fue evaluar la prevalencia de disritmias cardíacas
y de alteraciones del segmento ST en el perioperatorio por intermedio del Holter
en pacientes ancianos sometidos a cirugía de resección transuretral
de la próstata (RTU) y herniorrafia inguinal bajo raquianestesia.
MÉTODO: Fueron evaluados 21 pacientes con edades entre 65 y 84 años, sometidos a RTU de la próstata y 16 pacientes con edades de 65 a 86 años, sometidos a herniorrafia inguinal, bajo raquianestesia. Evaluación por el Sistema Holter en el pre-operatorio (12 horas), intra-operatorio (3 horas) y pos-operatorio (12 horas).
RESULTADOS: La prevalencia de extrasístoles supraventriculares (ESSV) entre los grupos RTU el control fue, en el pre-operatorio 85,7% vs. 93,7%, en el intra-operatorio 85,7% vs. 81,2% y en el pos operatorio de 76,2% vs. 100%. Las extrasístoles ventriculares (ESV) tuvieron prevalencia de 76,2% vs. 81,2% en el pre, 80,9% vs. 68,7% en el per y 80,9% vs. 81,2% en el pos-operatorio. La prevalencia de alteraciones del segmento ST entre los grupos RTU y control fue, no pre-operatorio 19% vs. 18,7%, en el intra-operatorio 4,7% vs. 18,7% y en el pos-operatorio de 14,3% vs. 18,7%, sin significancia estadística.
CONCLUSIONES: Los pacientes ancianos presentan alta prevalencia de ESSV y ESV. El número total de ESSV y ESV, y alteraciones del segmento ST, presentes en el período pre-operatorio, no fue alterado por la cirugía de resección transuretral de la próstata, bien como por la herniorrafia inguinal, en los períodos intra y pos-operatorio.
There is no clear definition for "old", "elderly" or "old age", as there is no specific clinic marker for geriatric patients since aging is not an abrupt, but rather a continuous process 1.
Geriatric population is uniquely heterogeneous 2. The World Health Organization, based on socio-economic factors, considers elderly all individuals aged 65 years or above. In Brazil, according to the law (8842, January 1994) elderly is all individuals aged 60 years or above 3. In general, physiological functions decrease 1% a year after 30 years of age, and at 70, baseline metabolism is 40% of normal 4.
Common preoperative elderly diseases are ECG changes, cardiovascular arteriosclerosis, previous myocardial infarction, congestive heart failure, liver and kidney diseases 5.
Elderly represent 25% of surgical patients and it is estimated that 50% of people above 65 years of age will undergo one surgery before death 6.
Several coronary disease patients have normal preoperative ECG 7. Silent myocardial ischemia (SMI) detected by long duration dynamic ECG (Holter System) is common during daily activities of asymptomatic patients with coronary disease and positive treadmill stress tests 8. In angina patients, 80% of ischemia are silent episodes 9. There is a high incidence of SMI in the first postoperative week, varying 21% 10 to 60% 11. The first clinical sign of perioperative ischemia is low cardiac output 11,12, arterial hypotension or arrhythmia 13.
The incidence of ECG changes in elderly increases with age, being observed: T wave and ST changes, supraventricular (SVPC) and ventricular (VCP) premature complexes and atrial fibrillation, intraventricular conduction abnormalities (right bundle branch block, left bundle branch block and first-degree atrioventricular block. Some are frequent in elderly patients (premature complexes, atrial fibrillation, left bundle branch block, intraventricular conduction abnormalities and ST changes), while others are better correlated to the presence of associated anatomic changes (pathological Q wave, right bundle branch block and left bundle branch block) 14. Bertrand et al. 15 (1971) have reported 48% incidence of arrhythmias during general anesthesia recovery, being 28% ventricular arrhythmias.
As people age, there are physiological heart changes affecting myocardium and conducting system, among others. These changes are not dependent on pathological changes, which are frequent in elderly. Several age-related heart electrophysiological changes are similar to those caused by diseases 16. Structural changes lead to collagen tissue and myocardial amyloidal matter increase and specific conduction tissue cells 17 and adrenergic stimulation sensitivity decrease 18.
Transurethral prostatectomy (TUP) is performed in elderly patients and is associated to considerable morbidity. Post-TUP cardiovascular deaths are 0.5% to 1%, increasing to more than 2% in patients above 80 years of age 19,20.
There are studies evaluating ST changes or acute myocardial infarction (AMI) during transurethral prostatectomy, but no studies were found evaluating the prevalence of intraoperative arrhythmias using dynamic ECG (Holter System) in patients submitted to this surgery under spinal anesthesia.
This study aimed at evaluating the prevalence of perioperative arrhythmias and ST changes through the Holter System in elderly patients submitted to transurethral prostatectomy (TUP) and inguinal hernia repair under spinal anesthesia.
After the Universidade Federal, Uberlândia Ethics Committee approval, participated in this randomized study 21 patients with benign prostate hypertrophy aged 65 to 84 years and submitted to TUP (Group TUP), and 16 patients with unilateral inguinal hernia (control group) aged 65 to 86 years and submitted to inguinal hernia repair under spinal anesthesia, in the period November 2001 through August 2002. All patients were informed about the research objectives and have signed the informed consent. Exclusion criteria were positive serology for Chagas disease, ST changes at ECG, liver and kidney diseases, anemia, infections and spinal anesthesia counterindications.
Patients were preoperatively evaluated by history, physical, lab and 12-lead ECG evaluation. Myocardial ischemia was defined as ST horizontalization or depression for 1 mm or more or ST increase of 2 mm or more during 60 seconds or more, followed by return to baseline for at least 1 minute 21.
Long duration dynamic ECG (Holter System) with Dynamics 3000 recorder was analyzed by the Cardiosystem program, release ALT V5 08C, 12 hours before anesthesia; during the surgical procedure from anesthesia beginning to completion with 3 hours duration, based on bupivacaine's duration which is 180 minutes 22; and 12 hours after anesthesia.
Cardiac rhythm: heart rate (bradycardia and sinus tachycardia); presence, classification (supraventricular or ventricular) and complexity (isolated, paired or cluster premature complexes) of arrhythmias, presence of atrioventricular blocks and/or of His bundle branches and ST changes were evaluated, considering pre, intra and postoperative periods.
Patients of both groups were not premedicated. Usual anti-hypertensive and cardiovascular drugs doses, except for aspirin, were maintained. Venous hydration was installed in the operating room 30 minutes before anesthesia with 500 mL lactated Ringer's. Monitoring consisted of cardioscope at CM5 lead, sphygmomanometer to control blood pressure by the Riva-Rocci method at 5-minute intervals, and pulse oximetry for continuous oxygen saturation (SpO2) reading. Spinal anesthesia was performed with patients in the right lateral position and previous skin infiltration with 1% lidocaine at puncture site. The needle was introduced medially at L2-L3 or L3-L4 with cephalad bevel, a 25G Quincke needle was used. After spinal space identification by the presence of CSF, 14 mg of 0.5% hyperbaric bupivacaine were injected.
Immediately after injection, patients were placed in the supine position until blockade is established evaluated by the loss of sensitivity to cold test. When the block reached T10 level patients were placed in the surgical position. If blood pressure reached 20% below baseline, ephedrine (10 mg) was administered. Postoperative analgesia was systematically induced with 1 g intravenous dipirone every 6 hours.
TUP was performed in the lythotomy position with continuous room temperature distilled water irrigation, up to 50 cm higher with regard to patients.
Non-parametric Wilcoxon's test was used for related samples to compare each group in the pre, intra and postoperative periods. Mann-Whitney's U test was used for independent samples to compare both groups in each evaluated period. Student's t test was used for independent samples when age, prevalence of bradycardia, arrhythmias and ST changes, and arrhythmias complexity were compared between groups.
For all tests, 0.05 or 5% (p < 0.05) was considered null hypothesis rejection level and significant values are identified with a asterisk (*).
Demographics data and physical status were homogeneous between groups (Table I).
During preoperative evaluation it has been observed that 2 group TUP patients had already previous acute myocardial infarction as compared to none in control group, with statistical significance. Other parameters were similar between groups and without statistical significance (Table II).
Preoperative evaluations were homogeneous between groups (Table III).
Table IV shows the incidence of sinus bradycardia (HR < 60), sinus pauses and ST changes, comparing TUP and control groups in the pre, intra and postoperative periods, as well as means by studied hour in each period, without statistical differences between groups, except for mean intraoperative sinus pauses in group TUP, where 1 patient had 107 pauses.
Table V shows total number of supraventricular and ventricular premature complexes in both groups and no statistical differences were found when periods of each group and both groups in each period were compared.
The loss of pacemaker and conducting cells in the elderly, by ischemia or conducting system structures degeneration, leads to conduction abnormalities, such as atrioventricular blocks and bundle branch blocks, as well as several arrhythmias; the incidence of ECG changes increases in parallel with increased age. Most frequent arrhythmias are: supraventricular and ventricular premature complexes (right bundle branch block, left blunde branch - partial or complete block), T wave and ST changes 14.
Continuous monitoring allows for the study of all types of cardiac arrhythmias, being reported an incidence of more than 80%, reaching 100% when intra-abdominal, chest, cardiovascular, neurological or major surgeries are performed. However, when there is casual inspection, only sporadic arrhythmias are observed and the incidence is below 20% 23. Hydroelectrolytic, metabolic and autonomic disturbances are among the main causes or worsening factors for perioperative arrhythmias 24.
Our study has observed bradycardia during all studied periods. The presence of conducting disorders and arrhythmias in the elderly does not necessarily mean the presence of heart disease 16. Major elderly heart changes are ventricular hypertrophy and left atrium increase, with consequences on cardiac rhythm 25. Sinus node has its total volume decreased, there is irregular destruction of peripheral areas with replacement by fatty tissue. Node constitution is changed with sinus cells decrease without connective tissue volume changes. This anatomic change would be responsible for intrinsic heart rate decrease 26.
One group TUP patient presented a very high number of intraoperative sinus pauses (107 pauses), which might have been due to vagal predominance (sick sinus syndrome) following spinal anesthesia sympathetic block. Patient was treated with parasympatholytic drug however without adequate response and was referred to pacemaker implant.
All supraventricular arrhythmias are found in the elderly and it seems that prevalence increases with age. Depending on the method used to detect arrhythmias, there are different prevalences. Tammaro et al. 27 (1983), using conventional ECG in 605 patients above 60 years of age, have found supraventricular arrhythmias in 33.2% of patients above 75 years of age and in 23.9% of patients with less than 75 years of age. Similar conclusions were drawn by a different study 28 with patients aged 40 to 90 years, which has found SVPC in 21.4% of patients below 60 years of age and in 74.2% of patients above 60 years of age. It has been observed 31% of SVPC in patients above 100 years of age as compared to 4% in the population aged 63 to 95 years and mean of 75 years of age 29.
Group TUP patients had 85.7% pre and intraoperative SVPC and 76.2% postoperative. Control group patients had 93.7% preoperative, 81.2% intraoperative and 100% postoperative SVPC (Table VI). SVPC were not responsible for a higher incidence of morbidity, which is in line with other authors 28,29.
No patient had atrial fibrillation, which is the most common elderly arrhythmia and is present in 0.4% of general population and in 3% to 5% of people above 65 years of age 30.
VPC was present in 30% to 84% of individuals with seemingly normal hearts at clinical and noninvasive tests (ECG, stress test and echocardiogram) 31. In a study by Rasmussen et al. 32 (1985) VPC has increased with age, being 31% in the group aged 20 to 39 years, 68% in the group aged 40 to 59 years and 84% in the group aged 60 to 79 years. Most (80%) had less than one ventricular premature complex/hour. Ventricular premature complex was in general uncommon, monomorphic and isolated in those patients.
Dietz et al. 33 (1987) have reported that 87.2% of elderly patients with mean age of 80 years had frequent premature complex when studied by Holter. Wajngarten et al. 25 (1990) have studied 26 patients above 70 years of age, where 77% had VPC in 23% they were frequent and in 50% they were polymorphic. Non-sustainable ventricular tachycardia was present in 11.5% of patients. Although ventricular mass increase with age was seen at echocardiogram, there has been no correlation with ventricular arrhythmias.
Continuous ECG records were used in two arrhythmia studies in a total of 254 patients submitted to non-cardiac surgeries 15,34. The incidence of arrhythmias was 70%, being 28% ventricular. The first study 34 was performed with 154 patients submitted to non-cardiac surgery, who presented a 62% incidence of arrhythmias. This incidence was higher during general anesthesia versus regional anesthesia (66% vs. 52%), neurological and chest surgeries versus peripheral surgeries (100%, 90% vs. 56%) and intubated versus non-intubated patients (72% vs. 44%). Ventricular arrhythmias (18% premature complexes and 3% ventricular tachycardia) were responsible for 21% of cases. Surprisingly, preexistent heart disease had no influence in the incidence of arrhythmias (62% vs. 59%). A different study 15 has found 84% of arrhythmias in 100 patients submitted to non-cardiac surgeries. Intraoperative incidence was significantly higher as compared to pre-induction phase (84% vs. 28%), especially during tracheal intubation and extubation, when there were 72% arrhythmias being 43% ventricular arrhythmias, with higher incidence in patients with preexisting heart disease (60% vs. 37%). These studies, however, have not identified age brackets.
Isolated ventricular arrhythmias in asymptomatic patients or with normal ventricular function were not risk factors for perioperative cardiovascular complications. However, complex and frequent ventricular arrhythmias with abnormal ventricular function were observed in the perioperative period, especially in patients with history of heart disease and have led to major complications and cardiac death. Patients with history of heart disease, abnormal ventricular function and frequent and complex ventricular arrhythmias had a higher number of complications and higher mortality rate 35. In our study, VPC was present in group TUP versus control in: 76.2% vs. 81.2% in the preoperative, 80.9% vs. 68.7% in the intraoperative, and 80.9% vs. 81.2% in the postoperative periods.
Differently from Marshall et al. 36 (1972) our study has shown that ventricular arrhythmias (isolated, paired and ventricular tachycardia) were not responsible for both intra and postoperative cardiovascular complications, and that in spite of the high prevalence of supraventricular and ventricular arrhythmias in this age bracket, there have been no significant differences when spinal anesthesia was used.
TUP has not increased the number of arrhythmias as compared to control group and no patient had TUP syndrome signs during the study.
Post-extracardiac surgery arrhythmias are frequent and may be triggered by other complications not inherent to heart, such as bleeding, infection, acid-base and hydroelectrolytic disturbances, and hypoxemia 36. Preoperative dynamic ECG (Holter System) may be indicated when there is suspicion of silent myocardial ischemia in heart disease patients. Several studies have shown the relationship between preoperative ST depression and the frequency of ischemic events. Mangano et al. 35 (1990) have shown 25% of intraoperative ischemic episodes in 200 patients. In a study involving 474 males at high risk or with known heart disease using two-channel Holter System monitoring during elective non-cardiac surgeries, two days before surgery, during surgery and two days after surgery, it has been observed that Holter-recorded myocardial ischemia before surgery has increased 9.2 times the risk for postoperative ischemia 35.
The interest in perioperative myocardial ischemia monitoring reflects the possibility of using it as a factor to predict adverse cardiac results, such as acute myocardial infarction, heart failure or death. Several risk factors have been identified in selected populations 37,38. However, severe adverse events (death, infarction or angina) are uncommon, even in patients at high risk. The detection of silent myocardial ischemia may help identifying this population at increased risk for cardiovascular adverse events.
Evans et al. 39 (1991) have quantified hemodynamic changes during TUP using transesophageal echocardiography and have observed an increase in left ventricle afterload indicating an increase in myocardial work and oxygen demand, which may result in myocardial ischemia contributing to cardiovascular morbidity and mortality. Heart rate and systolic volume are progressively decreased during the first 30 minutes of surgery, resulting in cardiac output decrease, with significant LV afterload increase since the beginning of the procedure. These findings have shown that hemodynamic responses non-detectable by conventional monitoring methods were present during TUP. Increased LV afterload indicates increased myocardial work and oxygen demand, which may result in myocardial ischemia and contribute to increased post-TUP cardiovascular morbidity and mortality.
Dobson et al. 40 (1994) have studied hemodynamic variables of patients submitted to TUP under general and spinal anesthesia and have concluded that both techniques are associated to major hemodynamic changes right after anesthetic induction, being more severe with general anesthesia. They have also observed that prostate resection period is not related to significant hemodynamic changes.
Edwards et al. 41 (1995) have studied perioperative myocardial ischemia incidence and duration using outpatient ECG in 100 patients submitted to transurethral prostatectomy and randomized to general or spinal anesthesia. Total myocardial ischemia went from 18% in the preoperative period to 26% in the postoperative period. Patients with ischemic disease had a significantly higher incidence of postoperative ischemia as compared to patients without previous ischemic disease. There has been increase in postoperative ischemia incidence and duration with both anesthetic techniques, however without significant difference between them.
In a prospective randomized study, Shalev et al. 42 (1999) have compared acute myocardial infarction incidence and morbidity in patients submitted to TUP, conventional prostatectomy and other non-cardiac surgeries. Post-prostatectomy AMI incidence with both techniques was higher than 6% as compared to other surgeries, where it is 2.5%. There have been no statistical differences in mortality, which has been 14.4% for TUP and 8.5% for conventional prostatectomies.
In our study, the incidence of ST changes for group TUP versus control was: 19% vs. 18.7% in the preoperative period, 4.8% vs. 18.7% in the intraoperative period, and 14.3% vs. 18.7% in the postoperative period without statistical differences between groups. These results are comparable to those found by Edwards et al. 41 (1995).
Supraventricular and ventricular arrhythmias, and ST changes were not responsible for intra and postoperative complications in both groups. We believe that a high number of premature complexes does not counterindicate transurethral prostatectomy in elderly patients.
Our conclusion was that elderly patients have a high supraventricular and ventricular arrhythmia prevalence and that the total number of preoperative supraventricular and ventricular arrhythmias and ST changes has not been changed by transurethral prostatectomy or inguinal hernia repair in the intra and postoperative periods.
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Dra. Beatriz Lemos da Silva Mandim
Rua Berenice Rezende Diniz, 300 - Casa 22 - Gávea
38411-162 Uberlândia, MG
Apresentado (Submitted) em 25 de
março de 2003
Aceito (Accepted) para publicação em 17 de junho de 2003
* Recebido do (Received from) Departamento de Anestesiologia da Universidade Federal de Uberlândia (UFU), MG