Sinan Gürsoy

Investigation of palpitations

The uncomfortable awareness of a beating heart--palpitations--is a common complaint that can occur under normal or abnormal circumstances. For example, normal palpitations occur with exercise, emotions, and stress, or after taking substances that increase adrenergic tone or diminish vagal activity (coffee, nicotine, and adrenergic or anticholinergic drugs). Normal palpitations are recognised as such because individuals who experience them realise or are told that something happened to accelerate the normal rhythm of the heart. However, some people find sinus tachycardia troublesome enough to seek medical attention. In other situations palpitations are clearly abnormal. The heart beat which is felt for no apparent reason, may be fast, or strong and slow, or feel like a missed or extra beat. Although these abnormal palpitations usually point to a cardiac arrhythmia, this is not always the case. Moreover, many patients with arrhythmias do not have palpitations but manifestations such as syncope, shock, and chest pain (sudden death is also possible). We will discuss the approach to the patient who seeks medical attention because of a history of palpitations, with special emphasis on the history, physical examination, and 12-lead electrocardiogram (ECG) because they are simple and inexpensive diagnostic tools that are available to most physicians.

Radiofrequency Ablation of Symptomatic but Benign Ventricular Arrhythmias

GURSOY, S., et al.: Radiofrequency Ablation of Symptomatic but Benign Ventricular Arrhythmias. Two cases are presented where ablation of severely symptomatic ventricular arrhythmias not responding to medical therapy was accomplished with radiofrequency current application. After a routine programmed stimulation protocol, a quadripolar ablation catheter with a 4‐mm tip was advanced percutaneously into the left ventricle in one case and into the right ventricle in the second case; and after precise pace mapping, the arrhythmogenic focus was successfully ablated using radiofrequency current. The postablation ambulatory recording revealed virtual eradication of ventricular ectopy in both cases. In conclusion, in severely symptomatic cases of “benign” ventricular arrhythmias, radiofrequency ablation offers an effective therapeutic alternative.

First Lessons from Radiofrequency Catheter Ablation in Patients with Ventricular Tachycardia

Fourteen patients (12 men, 2 women; 61 ± 9 years) with ventricular tachycardia and underlying heart disease underwent an attempt at radiofrequency energy catheter ablation. Twelve patients had coronary disease and two patients had dilated cardiomyopathy. Two patients had two clinical tachycardias, the ejection fraction was 38%± 11%. All tachycardias were inducible and hemodynamically well tolerated (cycle length = 357 ± 56 msec). Ablation was initially successful in nine patients (no tachycardia inducible after ablation and before discharge). Two patients had recurrences (in‐hospital and 4 months) and one patient had a tachycardia of a different morphology, which was also successfully ablated. Ablation was overall successful in seven patients and unsuccessful in seven patients (including all patients with cardiomyopaihy). Mid‐diastolic potentials were observed in all the patients in whom ablation was successful but not observed in four of seven unsuccessful patients. The successful patients remain free of recurrences at 9 ± 8 months follow‐up. Conclusions: (1) in ventricular tachycardia following an old infarction radiofrequency energy ablation is possible with a high success rate if a critical component of the tachycardia circuit can be localized. Localizing isolated mid‐diastolic potentials and ensuring these potentials are part of the reentrant circuit with concealed entrainment can help to enhance the results. (2) A negative predischarge electrophysiological study may be predictive of success.

Right‐Sided Versus Left‐Sided Radiofrequency Ablation of the His Bundle

Radiofrequency (RFJ ablation of the His bundle was attempted in 30 consecutive patients with atrial flutter or fibrillation. A 7 French quadripolar catheter with a 4‐mm distal electrode was advanced from the right femoral vein (21 patients), or subclavian vein (two patients) and positioned across the tricuspid valve. Adequate His‐bundle potentials were obtained in all patients. However, in six patients atrioventricular (AV) block could not be obtained after multiple (mean = 8) applications of RF energy from the conventional right‐sided approach. In these patients the same catheter was advanced to record a His potential through a retrograde arterial approach. AV block was created in all patients with one to three applications of RF energy. The duration of the procedure was 22 to 90 minutes for the right‐sided approach and 5 to 10 for the left‐sided approach (P < 0.005). Subsequently, in seven patients a left‐sided approach was used first. One to six applications of RF energy were required to create AV block. The radiation exposure time was 3 to 20 minutes. No complications occurred. Conclusions: RF ablation of the His bundle seems easier using a left‐sided than a right‐sided approach, reduces procedure and radiation time, and avoids recovery of conduction. These data suggest that a left‐sided approach, in spite of requiring arterial catheterization, may be preferable to a right‐sided approach.

Radiofrequency Current Catheter Ablation for Control of Supraventricular Arrhythmias

Radiofrequency Catheter Ablation in SVT. With the advent of radiofrequency energy, catheter ablation techniques have become an accepted form of treatment for a variety of Supraventricular arrhythmias. The ablation of the atrioventricular (AV) node was performed first and is now widely used in patients with refractory atrial fibrillation or flutter. Ablation has also replaced surgery in patients with preexcitation syndromes, and as the complication rate in experienced centers is low, it has become the first line of treatment in these institutions. The results of catheter ablation in AV nodal reentrant tachycardia are excellent as well, although there is still debate about whether “slow” pathway ablation is superior to “fast” pathway ablation. Radiofrequency current ablation has also contributed to a better understanding of the pathophysiology of AV nodal reentrant tachycardia, as it has provided evidence for atrial participation in the reentrant circuit. Experience with atrial tachycardias and tachycardias due to Mahaim fibers remains limited. The ideal source of energy for specific arrhythmias is still unknown and improvement in catheter technology is needed.

Mechanisms of sudden cardiac death.

SummaryAlthough coronary artery disease is the most frequent cause of sudden cardiac death, it may be caused by a heterogeneous group of disorders. Acute ischaemia is responsible for about half the cases of sudden death after acute myocardial infarction, and is manifested through ventricular fibrillation or polymorphic ventricular tachycardia. Several factors affect the haemodynamic consequences of a ventricular arrhythmia. Re-entry is the mechanism involved in patients with a history of myocardial infarction and therapy should be individualised and directed to the arrhythmia. Simple decision trees are available that can help to find the most appropriate therapy; implantable defibrillators are the most effective modality in certain very high risk subsets.

Value of clinical-variables for risk stratification in patients with sustained ventricular-tachycardia and history of myocardial-infarction.

Abstract In patients with coronary artery disease presenting with sustained ventricular tachycardia or fibrillation, assessment of the individual risk for cardiovascular death remains a clinical challenge. The usefulness of clinical history for risk stratification was examined in previous studies, 1–3 but with the establishment of cardiac catheterization 4–6 and programmed electrical stimulation 5,7,8 as standard techniques for clinical decision making, laboratory data gained enormous importance. We evaluated predictors of outcome in a homogeneous group of patients with old myocardial infarction presenting with ventricular tachyarrhythmias, and compared risk stratification exclusively based on variables derived from the patients history with that from programmed electrical stimulation and cardiac catheterization.

Cardiac depolarization and repolarization in Wolff-Parkinson-White syndrome.

Delta wave and QRS complex polarities have been extensively studied in preexcitation syndromes. However, only limited data exist about ventricular depolarization and repolarization in the setting of maximal preexcitation in relation to the site of insertion of the accessory pathway. Therefore this study was designed to systematically analyze cardiac depolarization and repolarization in patients with maximal preexcitation. We analyzed the polarity of the QRS complex and T wave on the frontal plane on the conventional 12-lead electrocardiogram in 118 patients with maximal preexcitation. Fast atrial pacing was used to provoke maximal ventricular preexcitation. The 32 patients with a left lateral accessory pathway showed right-axis deviation of the QRS complex (110 +/- 20 degrees) with a left-axis deviation of the T-wave axis (-40 +/- 25 degrees). The 54 patients with a posteroseptal accessory pathway had a left axis of the QRS complex (-50 +/- 20 degrees) with a right-axis deviation of the T-wave axis (95 +/- 15 degrees). The 11 patients with a right lateral accessory pathway had a left axis of the QRS complex (-40 +/- 20 degrees) and a right axis of the T wave (110 +/- 10 degrees). In 7 patients with a left anterolateral accessory pathway and 14 patients with a right anteroseptal accessory pathway, the axis of the QRS complex was 50 +/- 25 degrees and 45 +/- 20 degrees, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Bedside recordings of His-bundle electrograms using conventional twelve-lead surface electrocardiography.

Bedside Recording of His Potentials. Introduction: Endocavitary His‐bundle electro‐grams are usually recorded using high fidelity amplifiers and special filters.

Surgical treatment of cardiac arrhythmias. The physician’s point of view

The present therapeutic armentarium for the management of cardiovascular disease is enormous. We have at our disposal many pharmacologic and nonpharmacologic means to diminish or relieve ischemia, improve mechanical function of the heart, and to prevent or terminate an acute episode of cardiac arrhythmia. There are not, however, many cardiovascular diseases which can be truly cured. ‘Cure’ means the total suppression of symptoms, no need for any additional treatment, return of life expectancy to normal and an improvement in quality of life to such an extent that the patient can really forget that he (she) was ever ill.