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Background: CPVT (catecholaminergic polymorphic ventricular tachycardia) is a condition characterized by syncopes and cardiac arrest that was first described in 1975. CPVT has later been classified as a genetic disease with a great risk for life-threatening arrhythmias that are mainly caused by mutations in the ryanodine receptor 2 gene. Starting with a case report, we present an overview of CPVT., Material and Methods: The literature reviewed was identified through a non-systematic search in PubMed., Results: Diagnosing CPVT may be difficult, as resting ECG is normal and the syncopes may be misdiagnosed as epilepsy. Information about syncopes related to physical or emotional stress and occurrence of unexplained syncopes or cardiac arrest among family members, is important in the diagnostic evaluation. An exercise stress test often reveals the classical pattern of ventricular arrhythmias at heart rates above 100 beats/min. The diagnosis can be confirmed by genetic testing. By beta-blocker treatment and, if necessary, an ICD (implantable cardioverter defibrillator) the prognosis can be improved., Interpretation: CPVT is a serious disease with a poor prognosis when left untreated. It is a rare but important differential diagnosis in young individuals with syncopes or cardiac arrest. Genetic screening of relatives has made it possible to identify mutation carriers in affected families in order to provide them with preventive therapy.

Background: Long QT syndrome is characterised by inherited long QT interval on the ECG and increased risk for syncope and sudden death caused by arrhythmias. For Romano-Ward syndrome and Jervell and Lange-Nielsen syndrome DNA based diagnostics are available., Materials and Methods: This paper is a summary of our experience with DNA-based diagnostics of LQTS since the autumn of 2003. The diagnostic analyses are performed by sequencing the exons of five genes, KCNQ1, HERG, SCN5A, minK and MiRP1., Results and Interpretations: As of mid-January 2005, 56 probands with long QT syndrome have been referred for genetic testing. We have identified an underlying mutation in 64% of the patients. Mutations in the KCNQ1 gene are most frequent in Norwegian long QT syndrome patients, as 61% of the patients have their mutation in this gene. The detection of a mutation in the probands has led to genetic testing of 215 relatives; 99 out of these are heterozygous for the mutation present in the family. Heterozygous patients have been referred to a cardiologist. Of the 43 that have been referred to follow up at the department of cardiology at Rikshospitalet, 35 have started treatment with beta blockers to reduce the risk of arrhythmias. Thus, DNA-based diagnostics has clinical significance leading to prophylactic treatment of long QT syndrome patients. Compared to evaluation of ECG, which is negative in 30% of mutation carriers, the sensitivity of DNA-based diagnostics of relatives of probands with a known mutation, is close to 1.

Background: Inherited arrhythmogenic disorders are a group of genetically determined diseases characterised by ventricular tachyarrhythmias sometimes leading to sudden death. The molecular bases of these disorders are mutations in genes coding for various cardiac ion channels. The most common cardiac ion channel disease is the long QT syndrome. This syndrome is rare, but probably more common in Norway than previously expected. We have recently started genetic testing for cardiac ion channel disorders at Rikshospitalet University Hospital in Oslo. This review describes the current understanding of the etiology, prognosis and management of cardiac ion channel disorders, based on literature and our own clinical experience., Interpretation: Cardiac ion channel disorders may lead to sudden cardiac death. Prophylactic and life-saving therapies are available for many of these disorders. Therapy and risk stratification depend on the clinical presentation, the ECG pattern, and which gene is mutated. Genetic testing offers the opportunity to exclude individual family members as mutation carriers.

Background: Ibutilide is a novel class III antiarrhythmic agent used for the termination of atrial flutter and atrial fibrillation. It mainly affects membrane potassium currents (IKr) and prolongs the cardiac action potential. This effect is reflected as QT-interval prolongation in the ECG. Drugs that affect IKr-currents are known to cause malignant ventricular arrhythmia., Material and Methods: We report three patients with heart failure where ibutilide triggered malignant ventricular arrhythmias (sustained torsades de pointes)., Results: All patients experienced dramatic haemodynamic deterioration. One patient died because of sustained arrhythmia. Mode of action for ibutilide is described. Precautions that should be observed when using ibutilide are outlined., Interpretation: Ibutilide is contraindicated in patients with heart failure and should be used with caution in patients with ischaemic heart disease or previous myocardial infarction. Ibutilide-induced ventricular arrhythmias may be particularly difficult to treat in patients with heart failure.

Reduced heart rate variability (HRV) is an independent risk factor after myocardial infarction, indicating higher risk of fatal and nonfatal arrhythmias and of cardiac death in general. Analysis of HRV is also a valuable tool in clinical research, providing a non-invasive measurement of fluctuations in sympathetic and parasympathetic activation. We expect increased use of these methods, since new 24-hour: ECG-monitoring equipment is to be delivered with software for HRV as an option. Statistical time domain analysis of the whole 24-hour system of recording is very suitable for stratifying risk after myocardial infarction. Frequency domain analysis requires manual as well as automatic editing, but is the method of choice in clinical research involving short-term recordings and standardized conditions.

The authors discuss the potent antiarrhythmic drug amiodarone, with emphasis on indications, efficacy and side effects. At present the drug can be prescribed only by specialists in internal medicine. In order to monitor the efficacy of the drug and any side effects the patient should preferably be evaluated every three to six months. Use of intravenous amiodarone in hospital is effective in many cases but, so far, documentation on this treatment is limited.

Acute coronary syndrome is defined as unstable angina or acute myocardial infarction. A discussion on drug treatment of these conditions was arranged by the Norwegian Society of Cardiology and the Department of Pharmacotherapeutics, University of Oslo, soon after preliminary results of the GISSI II study were available. Relatively simple rules were agreed for the use of analgetics, nitrates and fibrinolytic agents. The last are used only after established myocardial injury. Consensus was also reached on the restricted use of calcium antagonists, inotropic agents and diuretics. There was disagreement concerning the dosage of heparin and the exact use of betablockers, aspirin, warfarin, ACE-inhibitors, magnesium and antiarrhythmics.

Sustained ventricular tachycardia and ventricular fibrillation are found to be the main causes of sudden cardiac death in out-of-hospital patients. Most of these patients do have serious organic heart disease, hence the arrhythmia must be regarded as a dangerous symptom. Of 44 consecutive patients referred for further investigation of either of these arrhythmias, organic heart disease was found in 43 (98%). Coronary heart disease and cardiomyopathy were the two most common illnesses found. Surgical treatment was efficient in cases of arrhythmias induced by myocardial ischaemia, and even patients with marked reduction in their left ventricular performance tolerated surgery well. As for the medically treated patients, the recurrence rate appeared to be lowest among those who received class-III-antiarrhythmic drugs.

The article reports a case of vasospastic angina. The disease is caused by a spasm in a large epicardial coronary artery which may otherwise be normal or show variable degrees of atherosclerosis. The diagnosis must be differentiated from acute myocardial infarction, unstable angina of arteriosclerotic origin and extracardial diseases. ECG may show transient elevation of the ST-segments and coronary arteriography can directly visualize the spasm during a spontaneous attack. Aggressive therapy with calcium antagonists and long-acting nitrates often has an excellent symptomatic effect and may improve the prognosis.