Hemodynamic effects of leg crossing and skeletal muscle tensing during free standing in patients with vasovagal syncope.

Physical maneuvers can be applied to abort or delay an impending vasovagal faint. These countermaneuvers would be more beneficial if applied as a preventive measure. We hypothesized that, in patients with recurrent vasovagal syncope, leg crossing produces a rise in cardiac output (CO) and thereby in blood pressure (BP) with an additional rise in BP by muscle tensing. We analyzed the age and gender effect on the BP response. To confirm that, during the maneuvers, Modelflow CO changes in proportion to actual CO, 10 healthy subjects performed the study protocol with CO evaluated simultaneously by Modelflow and by inert gas rebreathing. Changes in Modelflow CO were similar in direction and magnitude to inert gas rebreathing-determined CO changes. Eighty-eight patients diagnosed with vasovagal syncope applied leg crossing after a 5-min free-standing period. Fifty-four of these patients also applied tensing of leg and abdominal muscles. Leg crossing produced a significant rise in CO (+9.5%; P < 0.01) and thereby in mean arterial pressure (+3.3%; P < 0.01). Muscle tensing produced an additional increase in CO (+8.3%; P < 0.01) and mean arterial pressure (+7.8%; P < 0.01). The rise in BP during leg crossing was larger in the elderly.     

Physiological phenomenology of neurally-mediated syncope with management implications

Background

Due to lack of efficacy in recent trials, current guidelines for the treatment of neurally-mediated (vasovagal) syncope do not promote cardiac pacemaker implantation. However, the finding of asystole during head-up tilt –induced (pre)syncope may lead to excessive cardioinhibitory syncope diagnosis and treatment with cardiac pacemakers as blood pressure is often discontinuously measured. Furthermore, physicians may be more inclined to implant cardiac pacemakers in older patients. We hypothesized that true cardioinhibitory syncope in which the decrease in heart rate precedes the fall in blood pressure is a very rare finding which might explain the lack of efficacy of pacemakers in neurally-mediated syncope.

Methods

We studied 173 consecutive patients referred for unexplained syncope (114 women, 59 men, 42±1 years, 17±2 syncopal episodes). All had experienced (pre)syncope during head-up tilt testing followed by additional lower body negative suction. We classified hemodynamic responses according to the modified Vasovagal Syncope International Study (VASIS) classification as mixed response (VASIS I), cardioinhibitory without (VASIS IIa) or with asystole (VASIS IIb), and vasodepressor (VASIS III). Then, we defined the exact temporal relationship between hypotension and bradycardia to identify patients with true cardioinhibitory syncope.

Results

Of the (pre)syncopal events during tilt testing, 63% were classified as VASIS I, 6% as VASIS IIb, 2% as VASIS IIa, and 29% as VASIS III. Cardioinhibitory responses (VASIS class II) progressively decreased from the youngest to the oldest age quartile. With more detailed temporal analysis, blood pressure reduction preceded the heart-rate decrease in all but six individuals (97%) overall and in 10 out of 11 patients with asystole (VASIS IIb).

Conclusions

Hypotension precedes bradycardia onset during head-up tilt-induced (pre)syncope in the vast majority of patients, even in those classified as cardioinhibitory syncope according to the modified VASIS classification. Furthermore, cardioinhibitory syncope becomes less frequent with increasing age.     

Decrease in cardiac output and muscle sympathetic activity during vasovagal syncope

The importance of cardiac output (CO) to blood pressure level during vasovagal syncope is unknown. We measured thermodilution CO, mean blood pressure (MBP), and leg muscle mean sympathetic nerve activity (MSNA) each minute during 60 degrees head-up tilt in 26 patients with recurrent syncope. Eight patients tolerated tilt (TT) for 45 min (mean age 60 +/- 5 yr) and 15 patients developed syncope during tilt (TS) (mean age 58 +/- 4 yr, mean tilt time 15.4 +/- 2 min). In TT patients, CO decreased during the first minute of tilt (from 3.2 +/- 0.2 to 2.5 +/- 0.3 l x min(-1) x m(-2), P = 0.001) and thereafter remained stable between 2.5 +/- 0.3 (P = 0.001) and 2.4 +/- 0.2 l x min(-1) x m(-2) (P = 0.004) at 5 and 45 min, respectively. In TS patients, CO decreased during the first minute (from 3.3 +/- 0.2 to 2.7 +/- 0.1 l x min(-1) x m(-2), P = 0.02) and was stable until 7 min before syncope, falling to 2.0 +/- 0.2 at syncope (P = 0.001). Regression slopes for CO versus time during tilt were -0.01 min(-1) in TT versus -0.1 l x min(-1) x m(-2) x min(-1) in TS (P = 0.001). However, MBP was more closely correlated to total peripheral resistance (R = 0.56, P = 0.001) and MSNA (R = 0.58, P = 0.001) than CO (R = 0.32, P = 0.001). In vasovagal reactions, a progressive decline in CO may contribute to hypotension some minutes before syncope occurs.     

儿童直立调节试验对不明原因晕厥的诊断价值

目的:探讨直立倾斜试验对儿童不明原因晕厥的诊断价值,为临床诊断提供科学依据。方法:对208例不明原因晕厥的儿童给予进行直立倾料试验检查,持续进行心电监护监测,记录其血压、心率变化,分析试验结果。结果:145例(69.71%)出现阳性的血管迷走神经反应,73例(50.34%)为血管抑制型反应;19例(13.10%)呈心脏抑制型反应;53例(36.55%)为混合型反应型,并且诱发因子多为持久站立。结论:不明原因晕厥患者在直立倾斜试验中以血管迷走反应为主,持久站立是血管迷走神经性晕厥的主要诱因。     

The impact of diagnostic tests in evaluating patients with syncope

We reviewed the charts of 100 patients admitted to the hospital for evaluation of syncope. The charts were examined with special attention given to the causes of syncope, the frequency and benefit of diagnostic tests, and the relative cost of these tests. In 39 patients no etiology for syncope was found, and another 18 were felt to have had a vasovagal episode. Twelve patients had arrhythmias as the cause for syncope. Most of the patients underwent a variety of diagnostic tests including cardiac enzyme determinations, brain scans, electroencephalograms, head CAT scans, and Holter monitoring. In most instances, these tests added little useful information to the initial history and physical exam and were done at great expense to the patient. Our data suggest that extensive neurologic testing in patients with "routine" syncope is not warranted and that the focus of hospitalization should be to rule out potentially life-threatening arrhythmias.     

When the heart is stopped for good: hypotension-bradycardia paradox revisited

In vasovagal syncope, occurrence of bradycardia/asystole in the wake of hypotension has often been considered paradoxical. The major objective of this teaching module is to critically examine the pathophysiological mechanism and significance of the hypotension-bradycardia paradox unique to this condition. We narrate here how we discussed the pathophysiology of vasovagal syncope in a large classroom session attended by 275 doctors and medical students. A case study was used to describe the typical clinical presentation of vasovagal syncope. The pathophysiological mechanisms involved were then discussed systematically using a series of open-ended questions. We made it clear 1) that the occurrence of bradycardia or asystole in the face of acute severe hypotension is a mechanism to possibly minimize further blood loss, prevent myocardial damage, and increase ventricular filling; and 2) that fainting, which occurs as a consequence of this, is a homeostatic mechanism that serves to restore venous return and cerebral blood flow before blood pressure is normalized by neural reflex mechanisms. Eighty-four percent of participants reported that they were satisfied with the session. The information contained herein could be used to explain to any suitable audience the neural regulation of blood pressure in the face of acute severe hypotension and the pathophysiology of vasovagal syncope.     

The Implantable Cardiac Pacemaker

The transistorized implanted pacemaker is proving to be an effective and reliable method for long-term pacing of the heart. All patients suffering from Stokes-Adams seizures were first given a trial period of conservative therapy, including isoproterenol (Isuprel), ephedrine, atropine and steroids. Twenty-four pacemaker implants were performed on 23 patients over a 21-month period. The preoperative insertion of a pacemaker cardiac catheter was a very valuable safety precaution. In this way the heart could be safely and reliably paced during the period of preoperative assessment and during the critical periods of anesthetic induction and thoracotomy. Infection did not occur, probably because of careful gas sterilization of the units. Various models of pacemakers are compared, and the reasons for two pacemaker failures are presented. There were two early deaths and one late death in the series. The relationship of progressive coronary disease to recent infarction is stressed. Patients having intermittent heart block frequently showed the picture of “competing pacemakers” postoperatively, but without deleterious effect. Twenty patients, between 54 and 88 years of age, are alive and well at the time of reporting, with excellent pacemaker response and no further Stokes-Adams attacks.     

Syncope, cerebral perfusion, and oxygenation.

During standing, both the position of the cerebral circulation and the reductions in mean arterial pressure (MAP) and cardiac output challenge cerebral autoregulatory (CA) mechanisms. Syncope is most often associated with the upright position and can be provoked by any condition that jeopardizes cerebral blood flow (CBF) and regional cerebral tissue oxygenation (cO(2)Hb). Reflex (vasovagal) responses, cardiac arrhythmias, and autonomic failure are common causes. An important defense against a critical reduction in the central blood volume is that of muscle activity ("the muscle pump"), and if it is not applied even normal humans faint. Continuous tracking of CBF by transcranial Doppler-determined cerebral blood velocity (V(mean)) and near-infrared spectroscopy-determined cO(2)Hb contribute to understanding the cerebrovascular adjustments to postural stress; e.g., MAP does not necessarily reflect the cerebrovascular phenomena associated with (pre)syncope. CA may be interpreted as a frequency-dependent phenomenon with attenuated transfer of oscillations in MAP to V(mean) at low frequencies. The clinical implication is that CA does not respond to rapid changes in MAP; e.g., there is a transient fall in V(mean) on standing up and therefore a feeling of lightheadedness that even healthy humans sometimes experience. In subjects with recurrent vasovagal syncope, dynamic CA seems not different from that of healthy controls even during the last minutes before the syncope. Redistribution of cardiac output may affect cerebral perfusion by increased cerebral vascular resistance, supporting the view that cerebral perfusion depends on arterial inflow pressure provided that there is a sufficient cardiac output.     

Efficacy of Coronary Angioplasty on Long-Term Outcome in Elderly Chinese Patients with ST Elevated Myocardial Infarction

The benefit and efficacy of interventional coronary therapies in elderly patients is still a controversial subject, especially in parts of the world where traditional and conservative medicine is still mainstream. In China, the benefit of intervention is still questionable, hence, this study investigated the prognostic significance of coronary angioplasty on outcomes of elderly patients presenting with ST-segment elevated myocardial infarction (STEMI). The study cohort comprised of 270 elderly (age ≥ 75 years) patients who had confirmed STEMI. Some 116 patients underwent coronary angioplasty (called CA group) and their prognoses and survival over the short- and long-term periods (up to 80 months) were compared to 154 comparable patients who received a noninvasive, more conservative medical therapy (non-CA group). The subsequent Kaplan–Meier survival curves and statistical analyses were used to ascertain any difference between the groups. There was no significant differences between the two groups in terms of their clinical presentation, clinical risk, cardiac features, medications and medical procedures, except that the peak creatine kinase was significantly higher in the CA group. The success rate of interventional percutaneous coronary intervention observed in the CA group was 92.4% and during the hospitalization period, there were fewer deaths in the CA group (11 vs. 61 in the non-CA group). Furthermore, after 1-year and up to 7 years postsurgery, the CA group had a significant survival when compared to the non-CA cohort. Analysis of the longer-term data, using multivariate Cox regression analysis after 80 months indicated a hazard ratio of mortality for patients in CA group to be 0.283 (95% CI: 0.140–0.534, P < 0.001). Also, multivariate logistic regression analysis identified conservative treatment, chronic renal failure, cardiac arrhythmia, chronic lung disease and left ventricular ejection fraction, as predictors of higher long-term mortality in elderly patients with STEMI. In conclusion, this study clearly indicates that elderly Chinese patients with STEMI who undergo coronary angioplasty benefit and have a better survival rates in both the short- and long-term.     

Leg crossing, muscle tensing, squatting, and the crash position are effective against vasovagal reactions solely through increases in cardiac output.

Tensing of lower body muscles without or with leg crossing (LBMT, LCMT), whole body tensing (WBT), squatting, and sitting with the head bent between the knees ("crash position", HBK) are believed to abort vasovagal reactions. The underlying mechanisms are unknown. To study these interventions in patients with a clinical history of vasovagal syncope and a vasovagal reaction during routine tilt table testing, we measured blood pressure (BP) continuously with Finapres and derived heart rate, stroke volume, cardiac output (CO), and total peripheral resistance using Modelflow. In series A (n = 12) we compared LBMT to LCMT. In series B (n = 9), WBT was compared with LCMT. In series C (n = 14) and D (n = 9), we tested squatting and HBK. All maneuvers caused an increase in BP, varying from a systolic rise from 77 +/- 8 to 104 +/- 18 mmHg (P < 0.05) in series A during LBMT to a rise from 70 +/- 10 to 123 +/- 9 mmHg (P < 0.05) in series B during LCMT. In each maneuver, the BP increase started within 3-5 s from start of the maneuver. In all maneuvers, there was an increase in CO varying from 54 +/- 12% of baseline to 94 +/- 21% in WBT to a rise from 65 +/- 17% to 110 +/- 22% in LCMT in series A. No maneuver caused significant change in total peripheral resistance. We conclude that the mechanism underlying the effects of these maneuvers is exclusively an increase in CO.     

Efficacy of empirical cardiac pacing in syncope of unknown cause.

Cardiac pacing is often considered in patients with recurrent syncope after repeated attempts to document the cause have failed. To assess the results of this tactic we reviewed the records of 104 patients who had received pacemakers for known or suspected bradycardia between September 1973 and March 1985. The patients were classified retrospectively into three groups: group 1 (31 patients with a mean age of 73 years) had unequivocal documentation of bradycardia during syncope, group 2 (42 patients with a mean age of 71 years) had electrocardiographic or electrophysiologic evidence of potential bradycardia but no documentation during spontaneous syncope, and group 3 (31 patients with a mean age of 69 years) had a history "suggestive of" bradycardia-related syncope but no other evidence to support the diagnosis. The rates of recurrence of syncope during follow-up were 6.3%, 7.3% and 32.2% in groups 1, 2 and 3 respectively (p less than 0.01). In group 3 recurrence was more probable in patients with loss of consciousness for more than 2 minutes than in those who were unconscious for 2 minutes or less (p less than 0.05). The results suggest that pacemaker implantation is justified for recurrent syncope after extensive attempts to document a spell have failed if abnormal diagnostic test results suggest bradycardia as a possible cause. Empirical pacing is less satisfactory in patients with normal results of evaluation but may arguably be justified when patients have recurrent syncope with injury.     

Long QT syndrome with AV Wenckebaching & bundle branch block in a neonate

We present a case of 21-day-old neonate brought with history of 3 episodes of syncope. Evaluation revealed congenital long QT syndrome associated with long cycle atypical AV Wenkebaching with a long short cycle sequence related left bundle branch aberrancy. Syncope was attributed to multiple episodes of Torsades de Pointes, necessitating emergency epicardial pacemaker implantation. In addition, child was started on oral propranolol therapy. On 2 months follow up, child was stable with no ventricular high rate episodes during pacemaker interrogation.     

Mortalidad y factores pronósticos asociados en pacientes ancianos y muy ancianos hospitalizados con infección respiratoria COVID-19

IntroductionElderly patients with COVID-19 has a worse clinical evolution, being more susceptible to develop serious manifestations. The differences between the elderly and very elderly population, mortality and associated prognostic factors of SARS-CoV-2 infection have not been enough studied yet.MethodsAn observational study of 416 elderly patients admitted consecutively to Hospital General Universitario de Ciudad Real for COVID-19 respiratory infection from March 1st to April 30th, 2020. Data were collected including patient demographic information, medical history, clinical characteristics, laboratory data, therapeutic interventions and clinical outcomes during the hospitalization and after discharge, until June 15, 2020 with the aim of analyzing mortality, and associated prognostic factors.ResultsThe mean age was 84.43 ± 5.74 years old; elderly patients (75-84 years) were 50.2% of the sample and very elderly (≥ 85 years) the remaining 49.8%. In Cox regression model, mortality rate was higher in very elderly group (HR = 2.58; 95% CI: 1.23-5.38; P = .01), hypertensive (HR = 3, 45; 95% CI: 1.13-10.5; P = .03) and chronic kidney disease patients (HR = 3.86; 95% CI: 1.3-11.43; P = .02). In contrast, calcium antagonists (HR = 0.27; 95% CI: 0.12-0.62; P = .002) and anticoagulant therapy during hospitalization (HR = 0.26; 95% CI: 0.08 0, 83; P = .02) were associated with a longer time free of mortality.ConclusionsMortality rate was higher in very eldery patients compared with eldery; and in hypertensive and chronic kidney disease patients. Anticoagulation therapy and calcium chanel bloquers treatment during hospitalization were associated with a higher survival in the short-term follow-up in patients hospitalized with COVID-19.     

MRI and cardiac implantable electronic devices; current status and required safety conditions

Magnetic resonance imaging (MRI) has evolved into an essential diagnostic modality for the evaluation of all patient categories. This gain in popularity coincided with an increase in the number of implanted cardiac implantable electronic devices (CIEDs). Therefore, questions arose with regard to the MRI compatibility of these devices. Various investigators have reported the harmless performance of MRI in patients with conventional (non-MRI conditional) devices. The recently published European Society of Cardiology (ESC) guidelines on cardiac pacing and cardiac resynchronisation therapy (CRT) indicate that MRI can be safely performed in patients with an implanted pacemaker or ICD (MRI conditional or not), as long as strict safety conditions are met. This is a major modification of the former general opinion that patients with a pacemaker or ICD were not eligible to undergo MRI. This review paper attempts to elucidate the current situation for practising cardiologists by providing a clear overview of the potential life-threatening interactions and discuss safety measures to be taken prior to and during scanning. An overview of all available MRI conditional devices and their individual restrictions is given. In addition, an up-to-date safety protocol is provided that can be used to ensure patient safety before, during and after the scan.Key points• Historically, MRI examination of patients with a CIED has been considered hazardous.• Ongoing advances in technology and increasing usage of MRI in clinical practice have led to the introduction of MRI conditional CIEDs and to more lenient regulations on the examination of patients with non-conditional CIEDs.• MRI investigations can be performed safely in selected patients when adhering to a standardised up-to-date safety protocol.     

The Artificial Cardiac Pacemaker—Indications for Implantation

Extensive clinical experience has demonstrated that implantable cardiac pacemakers are safe and effective mechanisms for controlling symptoms and preventing the hazards of third degree heart block with Stokes-Adams syncope. Medical management of this disease does not provide reliable protection and life expectancy averages about two years after diagnosis. Hence the negligible surgical morbidity and mortality associated with pacemaker implantation justifies broad indications to implant one of the four commercially available battery-powered units.Elective implantation of a pacemaker should be considered in patients with persistent third degree heart block who have had: One or more episodes of Stokes-Adams syncope; surgical injury to the conduction system, regardless of syncopal attacks; evidence of low cardiac output with cardiomegaly secondary to bradycardia. Few if any other cardiac arrythmias are satisfactorily controlled by an electrical pacemaker.Emergency pacemaker control is obviously necessary for patients developing intractable or recurrent bouts of asystole. During the interval until an implantable unit can be obtained and sterilized, the patient may be controlled by intravenous isoproterenol or by an external pacemaker attached to a transvenous catheter electrode, a precordial skin electrode or a percutaneous myocardial wire electrode.     

老年急性心肌梗死并心源性休克冠状动脉介入治疗的临床效果分析

目的:对比分析介入治疗和保守治疗对急性心梗合并心源性休克的老年患者的治疗效果。方法:回顾性分析急性心肌梗死并心源性休克患者,共入选230例,按照医生评估进行分组治疗,分为介入治疗组和非介入治疗组,介入组患者120例,接受冠脉介入治疗;非介入组患者110例,接受非介入治疗。对比分析危险因素以及治疗效果。结果:介入组中心肌梗死病史及心衰病史患者明显高于非介入组(24.2%vs 20%P<0.05;25%vs 17.3%,P<0.05),经皮冠状动脉介入治疗与非介入治疗相比能显著降低急性心梗合并心源性休克的老年患者住院病死率(40.8%vs 71.8%,P<0.05),非介入治疗组心律失常发生率高于介入治疗组(26.7%vs 21.8%,P<0.05),同时非介入治疗组肺部感染及肾衰的发病率较高(11.8%vs 5.8%P<0.05;8.2%vs 2.0%,P<0.05)。结论:针对急性心梗合并心源性休克的老年患者制定治疗方案时,虽然介入治疗存在更多的并发症,但是可以显著改善患者预后。     

Complicaciones y pronóstico de pacientes ancianos diagnosticados de meningioma intracraneal

ObjectSurgical treatment in patients older than 70 years old with intracranial meningioma is still subject to controversy. The benefit/risk ratio of this surgery has not been assessed due to the lack of objective criteria. The aim of this study is to assess the surgical complications and outcomes in elderly patients in our centre.MethodA retrospective analysis was performed on patients with intracranial meningioma between January 2010 and March 2014. The incidence of post-surgical complications, as well as their associated risk factors, was also analysed. Functional outcomes were compared with Glasgow Outcome Scale and Karnofsky index with those who underwent surgery and those with conservative management. Finally, a comparison was made between patients younger than 70 years old operated on for intracranial meningioma.ResultsA total of 48 patients diagnosed with intracranial meningioma older than 70 years old, of which 37 were operated on and 11 were followed up with conservative management. There were no differences between the groups in neurological status at discharge (Glasgow Outcome Scale 5 67.6 vs. 72.2%, respectively). No differences were observed in functional outcome during 6 months of follow up in the Karnofsky index between surgical and non-surgical patients (P = .486). In the comparison between older and younger than 70 years old, there were no differences in the incidence of surgical complications (P = .64 in early complications and P = .23 in late complications).ConclusionThe results of the present study suggest that age should not be a limitation in surgical indications in patients older than 70 years old with intracranial meningioma. No statistical differences were found in functional status compared with conservative management or in surgical complications between younger and elderly patients.     

Permanent demand pacing for hypersensitive carotid sinus syndrome

Ten patients with proved hypersensitivity of one or both carotid sinuses and with symptoms of recurrent lightheaded spells and syncope had implanted a permanent transvenous demand pacemaker. In a follow-up course ranging from 6 to 55 months there has been no recurrence of lightheadedness or syncope in any of the patients. Six of the ten have had their battery packs replaced owing to routine battery exhaustion.     

老年膝关节骨性关节炎保守治疗与置换术的疗效对比分析

目的：比较老年膝关节骨性关节炎予以保守治疗以及外科膝关节置换手术的治疗效果,以探讨其合理的干预方法。方法：选 取我院2009 年1 月-2013 年12 月间收治的50 例临床资料完整的老年膝关节骨性关节炎疾病患者,将其根据治疗方式的不同分 为保守治疗组17 例以及外科手术治疗组33 例,手术方法为膝关节置换术。比较术后的KSS 评分情况,HSS评分、膝关节优良率。 结果：治疗后手术治疗组患者的KSS 评分较治疗前明显改善,P<0.05。治疗后外科手术组患者的HSS 各项评分均明显优于保守治 疗组,治疗后手术组患者的膝关节功能优良率达到了100 %（33/33）,明显优于保守治疗组35.29 %（6/17）的优良率,组间比较有统 计学差异,P<0.05。结论：对于老年膝关节骨性关节炎进行保守治疗可能不会对疾病的进展起到干预作用,而明确诊断的患者行全 膝关节置换术可以有效改善膝关节功能,提高生活质量。     

Povidone-iodine Irrigation - A Possible Alternative To Lead Extraction

Pocket infection and erosion remain the commonest (class 1) indication for pacemaker (PM) or implantable cardiac defibrillator (ICD) lead extraction. However, tranvenous lead extraction is not without significant risk of serious complications, particularly in patients with chronically implanted leads or ICD leads specifically. The paucity of cardiologists adequately experienced to undertake this high-risk procedure also means that its availability is limited to relatively few specialist institutions, yet more conservative 'lead-preserving' treatment options have not been well-reported. We describe the first reported case of a chronically eroded and infected ICD generator, managed conservatively with 5-days of povidone-iodine closed irrigation, followed by re-implantation of a new ICD on the contralateral side. With satisfactory long-term follow-up, this successfully averted the need for lead extraction in our elderly patient. We advocate the need for formal prospective evaluation of conservative therapeutic strategies of PM and ICD pocket infections. Although not gold standard, it provides an important therapeutic alternative in resource-limited areas.