Perioperative and postoperative arrhythmia in three-vessel coronary artery disease patients and antiarrhythmic effects of ischemic preconditioning.

OBJECTIVE: Sudden cardiac death caused by arrhythmia remains a major unsolved problem after coronary artery bypass grafting (CABG). Ischemic preconditioning (IP) has proved effective in suppressing ischemia reperfusion arrhythmias in animals and humans. The purpose of the present study was to establish whether IP reduces postoperative arrhythmias in three-vessel coronary artery disease patients undergoing CABG. METHODS: Forty-five patients with stable angina and three main coronary artery stenosis admitted for primary CABG surgery were randomized into an IP and a control group. The IP protocol entailed twice occluding the ascending aorta by cross-clamping for 2 min, followed by 3 min of reperfusion. Electrocardiography was continuously recorded from the day before surgery to the second postoperative day. RESULTS: During the recording, all patients developed SVES and VES after the operation. The incidences of SVT and ventricular tachycardia (VT) after surgery were 73.3 and 77.8%, respectively. IP significantly reduced VES events per hour during 2h after reperfusion. The SVT and VT incidence and events per hour were significantly lower in the IP group during 2h after reperfusion and 24h later. CONCLUSIONS: IP significantly reduced VES, SVT, and VT after surgery. The antiarrhythmic effect 24h after surgery indicates a delayed antiarrhythmic IP phenomenon in these patients. These findings would indicate that IP constitutes a potential additional myocardial protective strategy in multi-vessel diseased patients undergoing CABG.     

Arrhythmias in off-pump coronary artery bypass grafting and the antiarrhythmic effect of regional ischemic preconditioning

OBJECTIVE: The authors sought to establish whether regional ischemic preconditioning (IP) reduces ischemic reperfusion arrhythmias in patients who undergo off-pump coronary artery bypass grafting (OPCAB). DESIGN: A controlled, randomized, prospective study. SETTING: A university hospital. PARTICIPANTS: Thirty-two patients with left anterior descending coronary artery (LAD) or 2-vessel heart disease (including LAD) who were to undergo OPCAB were randomized into an IP and a control group. INTERVENTIONS: IP was induced by occluding the LAD twice for a 2-minute period followed by 3-minute LAD reperfusion before bypass grafting of the first coronary vessel. MEASUREMENTS AND MAIN RESULTS: Twenty-four-hour electrocardiography was recorded from the preoperative day to the second postoperative day. The heart rate (HR) was significantly elevated after surgery. Supraventricular extrasystole (SVES) events were similar before and after surgery. The incidence of patients with ventricular extrasystole (VES), supraventricular tachycardia (SVT), atrial fibrillation (AF), and ventricular tachycardia (VT) was significantly increased after the operation. Ventricular arrhythmias occurred mostly during anastomosis and the early reperfusion period and recovered 2 hours after reperfusion. Supraventricular tachyarrhythmias were mostly encountered 24 hours after reperfusion. IP significantly suppressed HR elevation, SVT, and VT after surgery. SVES, VES, and AF episodes were similar between the groups. CONCLUSIONS: Arrhythmia was a common phenomenon during and after an OPCAB procedure. The present IP protocol significantly suppressed HR elevation, the episodes of SVT, and the incidence of VT after surgery.     

The effects of advanced age on the incidence of supraventricular arrhythmias after pneumonectomy in dogs

Because advanced age is the strongest independent risk factor for the development of supraventricular arrhythmias after lung resection, we compared the incidence and premorbid events of supraventricular arrhythmias after pneumonectomy in young and elderly dogs with the aim of better understanding potential age-related arrhythmogenic mechanisms. Right pneumonectomy was performed in 15 male mongrel dogs ("old" > or =8 yr [n = 8], "young" <4 yr [n = 7]) and the electrocardiogram continuously recorded by an implantable telemetry system for 1 wk before euthanizing. After surgery, 7 of 8 older animals (88%) developed a total of 23 episodes of sustained (>30 s) paroxysmal supraventricular tachycardia (SVT), compared with 0 of 7 (0%) young dogs, P = 0.0014. Analysis of heart rate over the 60 min preceding the onset of SVT revealed a progressive increase in sinus rhythm beginning 15 min before the arrhythmia. Comparison of the heart rate and rhythm obtained in younger animals from the corresponding postoperative hour demonstrated that although older animals developed more atrial (P = 0.03) and ventricular premature contractions (P = 0.056) and episodes of nonsustained ventricular tachycardia (P = 0.01), heart rate was similar for both groups until the increase in elderly dogs preceding the onset of SVT. Histologic examination of the atria showed interstitial fibrosis in old but not young animals. In addition, 4 of 8 (50%) elderly animals exhibited an inflammatory response within the atria consistent with acute myo- and epicarditis. We conclude that elderly dogs have an increased supraventricular arrhythmogenic potential within the first week after pneumonectomy than younger animals, perhaps because of increased atrial fibrosis and inflammation. Heart rate analysis before SVT onset suggests that adrenergic predominance was a probable responsible trigger. IMPLICATIONS: In this canine pneumonectomy model, advanced age was associated with an increased incidence of supraventricular arrhythmias, perhaps because of increased atrial fibrosis and inflammation.     

Tachykarde Herzrhythmusstörungen

Emergeny medicine and critical care are fields that often require rapid diagnosis and intervention for specific emergent situations. These critical interventions can be lifesaving or severely debilitating depending on their appropriateness and timeliness. Supraventricular tachyarrhythmias include atrial fibrillation, atrial flutter, AV-nodal reentrant tachycardia with rapid ventricular response and preexcitation syndromes combined with atrial fibrillation. Ventricular tachyarrhythmias still remain one of the leading causes of death; these arrhythmias include monomorphic and polymorphic ventricular tachycardia, torsade de pointes tachycardia, ventricular fibrillation and ventricular flutter. In the assessment of patients with supraventricular/ventricular tachyarrhythmias, attention should be given to identify whether the tachycardia is associated with worsening angina or low cardiac output. In patients with narrow QRS complex tachycardias or patients with atrial fibrillation and preexcitation syndromes immediate synchronised cardioversion should be performed if signs or symptoms of instability (hypotension, evidence of end-organ dysfunction, worsening angina) exist. In patients with a stable hemodynamic situation, vagal maneuvers, adenosine or calcium channel blockers can be used. In the treatment of patients with deemed unstable ventricular tachycardia (VT), electrical cardioversion is the treatment of choice. In more stable patients, ajmaline is the preferred agent after myocardial infarction and lidocaine if myocardial ischemia is present. In patients with torsade de pointes tachycardias aggressive steps must be taken to prevent degeneration of this rhythm to ventricular fibrillation (VF). Magnesium sulfate has recently been demonstrated efficacious and is currently considered first-line drug therapy. Patients with pulseless VT or VF demands early electrical countershock. In patients with ventricular fibrillation refractory to cardioversion amiodarone (300 mg i.v.) should be used.     

Untreated preoperative depression is not associated with postoperative arrhythmias in CABG patients

Purpose

The mechanism by which depression affects postoperative outcome may involve arrhythmias. The purpose of this study was to evaluate whether untreated depression is associated with an increased incidence of postoperative arrhythmias in patients undergoing coronary artery bypass graft surgery (CABG).

Methods

One hundred seven patients were assessed for signs of depression with the Prime-MD Patient Health Questionnaire (brief PHQ) one week before surgery and subsequently underwent Holter monitoring for 48-72 hr postoperatively. The incidences of atrial fibrillation (AF); supraventricular tachycardia (SVT); ventricular tachycardia (VT), defined as three or more consecutive beats at a cycle length less than 600 msec; ventricular fibrillation (VF); and average heart rate (HR) were recorded in patients with and without signs of depression.

Results

The incidence of preoperative untreated depression was 27% (29/107). Twenty patients had mild depression (brief PHQ score of 5-9), seven patients had moderate depression (a score of 10-14), and two patients had severe depression (a score of 20). The incidences of postoperative AF, SVT, and non-sustained VT in depressed and non-depressed patients were 37.9% vs 35.9%, respectively (P = 0.50), 34.4% vs 52.5%, respectively (P = 0.07), and 17.2% vs 37.1%, respectively (P = 0.04). The average (SD) postoperative HR was similar in both groups [95 (12) beats·min^?1 in depressed patients and 92 (10) beats·min^?1 in non-depressed patients, (P = 0.25)]. Multivariate regression analysis showed that older age, but not depression, was a risk factor for postoperative arrhythmia.

Conclusions

Preoperative untreated depression is not related to postoperative arrhythmia in the early postoperative period in patients undergoing elective CABG. This trial was registered at clinicaltrials.gov (number: NCT00622024).     

Ischemic preconditioning protects right ventricular function in coronary artery bypass grafting patients experiencing angina within 48-72 hours

BACKGROUND: To test whether ischemic preconditioning (IP) is able to protect the myocardium in recently unstable CABG patients. METHODS: Experimental design: prospective, randomised, controlled clinical study. Setting: University Hospital. Patients: Forty CABG patients with recent unstable angina were randomised into an IP group (n=20) and a control group (n=20). Subgroup was divided based on the time of the most recent ischemia onset before the operation. Intervention: The IP group was preconditioned with 2 cycles of 2-min ischemia followed by 3-min reperfusion before cross clamping. Measures: Hemodynamic data were monitored till the 1st POD. Biochemical markers were measured till the 2nd POD. RESULTS: There were no differences in cardiac index (Cl) and right ventricular ejection fraction (RVEF) in patients experiencing angina within 48 hours prior to operation. The percentage changes in CI and RVEF at 1 hour after declamping were significantly better in the IP group in patients experienced angina within 48-72 hours (106% vs 88% of baseline, p=0.027 and 103% vs 81% of baseline, p=0.023). No difference in postoperative cardiac troponin I (CTnI) and CK-MB was found between the IP and controls in either subgroup. CONCLUSIONS: IP has a beneficial effect on global and right ventricular hemodynamic functional recovery in unstable CABG patients experiencing angina within 48-72 hours prior to the operation. However, IP has no additional protective effects in unstable CABG patients who experience angina within 48 hours.     

Evaluation of a Novel Pulsatile Extracorporeal Life Support System Synchronized to the Cardiac Cycle: Effect of Rhythm Changes on Hemodynamic Performance

Arrhythmias are a frequent complication during extracorporeal life support (ECLS). A new ECLS system can provide pulsatile flow synchronized to the patient's intrinsic cardiac cycle based upon the R wave of the electrocardiogram (ECG). It is unclear how the occurrence of arrhythmias may alter the hemodynamic performance of the system. This in vitro study evaluated the effect of simulated arrhythmias on hemodynamics during R wave‐triggered pulsatile ECLS. The ECLS circuit with an i‐cor diagonal pump and iLA membrane ventilator was primed with whole blood at room temperature. Flow and pressure data were collected at 2.5 and 4 L/min for each condition using a customized data acquisition system. Pulsatile ECLS flow was R wave synchronized to an ECG simulator using 1:1, 1:2, and 1:3 assist ratios. Conditions tested included sinus rhythm at 45 and 90 bpm, supraventricular tachycardia (SVT), ventricular tachycardia (VT), and irregular rhythms such as ventricular fibrillation. Pulsatile mode was successfully triggered by ECG signals of normal sinus rhythm, SVT, VT, atrial fibrillation, atrial flutter, and ventricular bigeminy with assist ratios 1:1, 1:2, and 1:3. Regular rhythm at 90 bpm generated the best surplus hemodynamic energy (SHE). For SVT and VT, an assist ratio of 1:2 resulted in maximum pulsatile flow waveforms with optimal SHE at 2.5 L/min flow rate. At 4 L/min, SHE declined and the pressure drop increased independent of arrhythmia condition. Irregular rhythms still produced adequate pulsatile wave forms at lower pulsatile frequency. This study demonstrated the feasibility of generating pulsatile ECLS flow with the novel ECG‐synchronized i‐cor system during various simulated rhythms. The optimal rate for pulsatile flow was 90 bpm. During irregular rhythms, the lower pulsatile frequency was the more reliable synchronization mode for generating pulsatile flow.     

Efficacy of low-dose propranolol in preventing postoperative supraventricular tachyarrhythmias: a prospective, randomized study.

A prospective, randomized study was performed in 100 consecutive patients undergoing coronary artery bypass surgery to assess the efficacy of the early reinstitution of propranolol in reducing the incidence of postoperative supraventricular tachyarrhythmias (SVT). Patients were randomized to receive propranolol 10 mg every 6 hours enterally starting the morning after surgery (Group I, 50 patients) or to serve as controls (Group II, 50 patients). No patient was excluded because of poor ventricular function, need for urgent revascularization, or transient necessity for ionotropic support. Both groups had a comparable incidence of risk factors, previous infarction, unstable angina, and abnormal ventricular function. The extent of coronary disease, preoperative propranolol dose, and number of grafts performed were also similar. SVT occurred in 3/50 (6%) patients in Group I compared with 14/50 (28%) in Group II (p less than 0.01). There were no preoperative or intraoperative discriminators to predict the occurrence of SVT. In addition, perioperative infarction and the need for mechanical or pharmacologic circulatory support did not predispose to SVT. The data indicate that early administration of propranolol should be given to all patients after myocardial revascularization to decrease the incidence of these postoperative rhythm disturbances.     

Influence of clinical and hemodynamic variables on risk of supraventricular tachycardia after coronary artery bypass

The influence of 45 variables on risk of postoperative supraventricular tachycardia was evaluated by univariate and multivariate analysis of data from 800 consecutive patients who underwent isolated coronary artery bypass during a 6-year interval. Postoperative supraventricular arrhythmias occurred in 186 patients (23%) but did not contribute to any of the six early deaths (30-day mortality rate, 0.8%). Mean (+/- standard deviation) length of hospital stay was longer (9.8 +/- 5.7 versus 8.3 +/- 3.5 days; p less than 0.0001) and mean age was older (65 versus 60 years; p less than 0.002) in patients with postoperative supraventricular tachycardia than in those with regular rhythm. Risk of supraventricular tachycardia was increased in patients with a history of atrial arrhythmias (45% versus 22%; p less than 0.002) or premature atrial contractions on the preoperative electrocardiogram (48% versus 22%; p less than 0.002). Multiple logistic regression analysis identified age 65 years or more, history of atrial arrhythmia or preoperative premature atrial contractions, and preoperative left ventricular end-diastolic pressure 20 mm Hg or more as independent predictors of postoperative supraventricular tachycardia. Six percent of patients converted to sinus rhythm spontaneously; 82% of patients converted within 1.1 +/- 1.9 days after onset of supraventricular tachycardia on treatment with digoxin or beta-adrenergic blocking drugs or both. Only 10% of patients with supraventricular tachycardia required electrical cardioversion. We conclude that the risk of supraventricular tachycardia after coronary artery bypass is influenced by patient-related variables and is effectively managed by conventional therapy. Prophylactic treatment should be reserved for elderly patients, especially those who have atrial arrhythmias or have preoperative left ventricular end-diastolic pressure 20 mm Hg or more.     

Das Elektrokardiogramm 100 Jahre nach Einthoven

The surface electrocardiogram (ECG) is an important diagnostic tool even 100 years after the studies of Einthoven, particularly for diagnosis of arrhythmias and acute coronary syndrome. Supraventricular tachycardias (SVT) are paroxysmal tachycardias as sinus tachycardia, atrial tachycardia, AV-nodal reentry-tachycardia and tachycardia due to accessory pathways. SVT are characterized by a ventricular heart rate >100/min and small QRS complexes (QRS width <0,12 s) during tachycardia. It is important to analyze the relation between p wave and QRS complex, to look for an electric alternans as a leading finding for an accessory pathway. Wide QRS complex tachycardias (QRS width ≥0,12 s) occur in SVT with aberrant conduction, SVT with bundle branch block or ventricular tachycardia (VT). In broad complex tachycardias, AV dissociation, negative or positive concordant pattern in V1–V6, a notch in V1 and qR complexes in V6 in tachycardias with left bundle branch block morphologies are findings indicating VT. In addition, a R/S-relation in V6 favors VT when right bundle branch block tachycardia morphologies are present. By analyzing the surface ECG in the right way with a systematic approach, the specificity and sensitivity of correctly identifying a SVT or VT can be raised >95%.     

Prophylaxis of supraventricular and ventricular arrhythmias after coronary artery bypass grafting with low-dose sotalol

BACKGROUND: Supraventricular tachyarrhythmia (SVT) commonly occurs shortly after coronary artery bypass grafting (CABG), but ventricular arrhythmias are less documented. METHODS: On the 1st postoperative day, 206 consecutive eligible patients were prospectively randomized to a sotalol group (80 mg b.i.d.; n = 103) or a control group without beta-blockade or antiarrhythmic drugs (n = 103). RESULTS: The SVT incidence (predominantly atrial fibrillation) accounted for 16% in the sotalol group versus 48% (p < 0.00001). Multivariate analysis showed that sotalol reduced the SVT incidence (p < 0.00001, odds ratio, 0.20; 95% confidence interval, 0.09 to 0.42), whereas a lower preoperative left ventricular ejection fraction (p = 0.019) and older age (p = 0.031) were independent risk factors of SVT occurrence. The Holter electrocardiographic analysis (24 hours) demonstrated that sotalol (32 versus 92; p = 0.031) decreased the median number of ventricular events, mostly isolated premature ventricular beats. Neither ventricular proarrhythmia effect nor "torsades de pointes" were detected. Despite strict hemodynamic-based selection, sotalol had to be discontinued in 8 patients (7.8%), for reasons related to asthma in 3 or cardiac reasons in 5. CONCLUSIONS: Oral low-dose sotalol provided considerable and reliable protection in selected nondepressed cardiac function patients, reducing the occurrence of both supraventricular and ventricular arrhythmias after CABG.     

Antiarrhythmic effects of magnesium sulphate. Report of three cases

A wide variety of antiarrhythmic agents is used in treatment of both supraventricular and ventricular arrhythmias. Magnesium sulphate has previously been used mainly in the treatment of torsade de pointe arrhythmias but several reports show that this agent may be used in the treatment of arrhythmias of different aetiology. We describe 3 patients who exhibited arrhythmias affecting haemodynamic performance. Case #1 had a subarachnoid haemorrhage and developed a supraventricular tachycardia. In case #2, ventricular tachycardia appeared during the postoperative course after abdominal surgery. Case #3 experienced critical heart failure due to dilated cardiomyopathy and had an irregular heart rhythm with multiple ectopic beats. In all three cases the administration of intravenous magnesium sulphate was successful in treating the arrhythmias. Magnesium sulphate is an antiarrhythmic agent that is effective mainly in treatment of ventricular arrhythmias. The drug can also be employed as second-line treatment of supraventricular arrhythmias.     

The calcium sensitizer levosimendan and cardiac arrhythmias: an analysis of the safety database of heart failure treatment studies

BACKGROUND: Levosimendan is a calcium sensitizer that increases the contractility of the myofilaments and is considered not to affect cardiac electrophysiology. We assessed its potential to generate cardiac arrhythmias by analysing ECG recordings from clinical studies on intravenously administered levosimendan in heart failure patients. METHODS AND RESULTS: The database consisted of continuous 1-day recordings, of which 366 were during levosimendan and 142 during placebo comparison. Supraventricular (SVT) and ventricular tachycardia (VT) were defined as > or =3 premature complexes at a rate > or = 120/min. No difference appeared between levosimendan and control groups in the occurrence of atrial fibrillation (12% vs 13%), SVT (28% vs 30%), or VT (41% vs 44% of all recordings; all p = NS). Also the frequency of VT was similar (0.55 +/- 3.89 vs 0.20 +/- 1.08 episodes/h; p = NS). No torsade de pointes or sustained VT occurred. CONCLUSION: Short-term levosimendan therapy of heart failure showed no tendency to increase cardiac arrhythmias. Although assessing only surrogates of prognostically significant arrhythmias, the findings together with previously observed reduction of mortality in heart failure therapy studies support the presumption that levosimendan has an electrophysiologically neutral profile.     

Surgery for supraventricular tachycardia (SVT)

All forms of supraventricular tachycardia (SVT) are now potentially curable by surgery and we believe that patients should be offered surgery as an initial therapeutic option. At Westmead Hospital, 311 patients have undergone surgery for SVT, 13 having AV node ablation, a procedure now rarely performed, and 298 have had attempts at curative surgery. One hundred and ninety-nine patients were diagnosed primarily as having a Wolff-Parkinson-White syndrome (WPW) and 139 had free wall or anterior septal connections with a clinical cure rate of 98.0%. The failures were entirely due to unrecognised posterior septal connections. Sixty patients had primarily posterior septal connections with a clinical cure rate of 96%. Atrioventricular junctional re-entry tachycardia may now be cured, probably by dividing an extra nodal His-to-atrial connection. Seventy-eight patients have undergone surgery with a clinical cure rate of 92%. Fifteen patients with right atrial tachycardias, 4 patients with nodo-ventricular fibres and 2 with incessant AV tachycardia have undergone surgery. The overall clinical cure rate for all patients is 95% and 92% at late electro-physiological study (EPS).     

Incidence of arrhythmias after thoracic surgery: Thoracotomy versus video-assisted thoracoscopy

Atrial arrhythmias, especially supraventricular tachycardia (SVT) and atrial fibrillation, are common after thoracotomy and lung surgery. There are few existing data on the incidence of postoperative arrhythmias after video-assisted thoracoscopy (VAT). The purpose of the present investigation was to retrospectively determine the incidence of postoperative arrhythmias in patients who underwent VAT compared with those who underwent thoracotomy, and which factors are associated with an increased risk for arrhythmias in both groups. A retrospective investigation. A metropolitan university hospital. The medical records of 124 patients who underwent thoracotomy and 81 patients who underwent VAT over a 2-year period were reviewed.

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There was a 17% incidence of atrial arrhythmias after thoracotomy and 10% after VAT, but the difference was not statistically significant. In both groups, atrial fibrillation was the most common atrial arrhythmia. Patients receiving digoxin were at higher risk for postoperative arrhythmias. Patients older than 65 years were at risk for arrhythmias after thoracotomy and patients older than 80 years were at risk for arrhythmias after VAT. Patients who had postoperative arrhythmias had prolonged hospital stays compared with patients who did not have arrhythmias.     

Nifekalant hydrochloride as an effective treatment for postoperative ischemic heart disease

We experienced 2 effective cases of nifekalant hydrochloride. One patient was 76-year-old female who underwent emergent coronary artery bypass grafting (CABG) because of unstable angina pectoris (AP) and ventricular fibrillation (Vf). Her cardiac function had been decreased preoperatively due to old myocardial infarction (OMI). One day after CABG, she revealed sustained ventricular tachycardia (VT) and Vf. Although administrations of neither lidocaine hydrochloride nor magnesium sulfate were effective, nifekalant hydrochloride finally stopped the life-threatening arrhythmia without hypotension. Another patient was 77-year-old male who underwent CABG and Dor operation. His cardiac function also had been decreased due to OMI. He revealed VT attack at midnight 3 days after operation. VT attack still appeared at next 2 midnight under lidocaine hydrochloride infusion, but finally it has disappeared after starting a drip infusion of nifekalant hydrochloride. Nifekalant hydrochloride is quite useful as a new therapeutic strategy for uncontrollable VT and Vf and for the patient who has a reduced left ventricular function because it has an inotropic effect.     

Metoprolol and coronary artery bypass grafting surgery: does intraoperative metoprolol attenuate acute beta-adrenergic receptor desensitization during cardiac surgery?

Cardiac surgery results in significant impairment of beta-adrenergic receptor (beta AR) function and is a cause of depressed myocardial function after surgery. We previously demonstrated that acute administration of beta AR blocker during cardiopulmonary bypass (CPB) in an animal model of coronary artery bypass grafting (CABG) surgery attenuates beta AR desensitization, whereas chronic oral beta-blockade therapy in patients undergoing CABG surgery does not prevent it. Therefore we hypothesized that acute administration of metoprolol during CABG surgery would prevent acute myocardial beta AR desensitization. A placebo-controlled initial phase (n = 72) was performed whereby patients were randomized to either metoprolol 10 mg or placebo immediately before CPB. Then a second dose-finding study was performed where patients received 20 mg (n = 20) or 30 mg (n = 20) of metoprolol. Hemodynamic monitoring, atrial membrane adenylyl cyclase activity, atrial beta AR density, and postoperative outcomes were measured. All groups showed similar decreases in isoproterenol-stimulated adenylyl cyclase activity (13%-24%). Cardiac output remained similar in all 4 groups throughout the intraoperative and postoperative period. In addition, patients receiving metoprolol 20 or 30 mg had less supraventricular arrhythmias 24 h postoperatively compared with patients receiving metoprolol 10 mg or placebo. Therefore, unlike our previous animal model of CABG surgery, metoprolol did not attenuate myocardial beta AR desensitization. IMPLICATIONS: We investigated whether IV metoprolol given during cardiac surgery attenuates myocardial beta-adrenergic receptor (beta AR) desensitization. Although metoprolol did not reduce beta AR desensitization, the incidence of supraventricular arrhythmias was reduced by 75% in patients receiving 20 mg or 30 mg metoprolol.     

Tachykarde Rhythmusstörungen in der Notfall- und Rettungsmedizin: Von der Tablette bis zur Ablation

Tachycardiac arrhythmia (heart rate >100/min) requires rapid and targeted therapeutic strategies. Supraventricular tachycardia (SVT), such as sinus tachycardia atrial tachycardia, AV-nodal re-entry tachycardia and tachycardia due to accessory pathways are paroxysmal forms of tachycardia. All SVTs are usually characterized by small QRS complexes (QRS width <120 ms) during tachycardia. It is essential to evaluate the history of arrhythmia, to perform a thorough physical examination and to accurately analyze the 12-lead electrocardiogram. An exact SVT diagnosis is then possible in >90% of patients. Ventricular tachycardia (VT) has a broad QRS complex (QRS width ≥120 ms), ventricular flutter and ventricular fibrillation and is associated with chaotic electrophysiologic findings. For acute therapy of SVT vagal maneuvers, adenosine, class I anti-arrhythmic drugs, beta-blocking agents and calcium antagonists (type verapamil) can be used. If this therapy fails electrical DC cardioversion is mandatory. In patients with VT amiodarone is the treatment of choice as well as in patients with ventricular fibrillation or ventricular flutter refractory to cardioversion or defibrillation.     

Treatment of Tachyarrhythmias and Bradyarrhythmias by Cardiac Sympathectomy and Permanent Ventricular Pacing

There exists a group of patients who develop concomitant bradycardia and tachycardia that is unresponsive to routine medical management. These patients represent difficult therapeutic challenges, because treatment of the supraventricular or ventricular tachycardia may often “unmask” a bradycardia which may have a slow ventricular response—atrioventricular dissociation or even complete heart block. During routine treatment of this slow rhythm the supraventricular or ventricular tachycardia may be discovered.Brady/tachycardias or ventricular tachycardia in a patient having a normal coronary and valvular system proved refractory to routine medical management. Complete suppression of the arrhythmias was accomplished by cardiac sympathectomy and right ventricular pacing.     

Acute fatal vasoplegia and asystole induced by intravenous amiodarone after cardiopulmonary bypass in a patient with preoperative cardiogenic shock

Single dose intravenous amiodarone has been widely used and shown to be effective to treat supraventricular and ventricular arrhythemias in cardiac surgery. We, herein, report a 60-year-old female patient, sustaining cardiogenic shock in the course of percutaneous transluminal coronary angioplasty (PTCA) for unstable angina unrelieved by medication including nitroglycerin, succumbed to a life-saving emergent coronary artery bypass grafting (CABG) operation at the end of cardiopulmonary bypass (CPB) following a 180 mg bolus dose of amiodarone (3 mg/kg) directed at the ventricular arrhythmias, triggered by protamine and unresponsive to lidocaine treatment. Amiodaroneinduced asystole and vasoplegia were thought to be the causation of the failure of resuscitation. The causes of the development of these complications, the potential hazards of its use and the management relative to the consequential complications are reviewed and discussed.