Zeitschrift für Kardiologie
-
Comparative Study
Surgery of acute type A dissection: what have we learned during the past 25 years?
Every acute dissection involving the ascending aorta (Stanford type A) must undergo emergency surgical repair. However, the surgical techniques must vary according to the clinical presentation of the patients or the anatomical patterns observed. Furthermore, surgery is generally difficult because of the poor condition of the aortic tissues. ⋯ During CPB, perfusing the aorta in the regular antegrade manner seems to dramatically reduce the rate of malperfusion. The quality of the first emergency operation seems to have a major influence on the late results, especially concerning the rate of late reoperations and aortic ruptures. However, those late results depend also on the patient's basic condition, particularly in Marfan patients.
-
Comparative Study
[Percutaneous myocardial laser revascularization (PMR), a new therapeutic procedure for patients with refractory angina pectoris].
In patients with severe angina pectoris due to coronary artery disease, who are not candidates for either percutaneous coronary angioplasty or coronary artery bypass surgery, transmyocardial laser revascularization (TMR) often leads to improvement of clinical symptoms and increased exercise capacity. One drawback of TMR is the need for surgical thoracotomy in order to gain access to the epicardial surface of the heart. Therefore, a catheter-based system has been developed, which allows creation of laser channels into the myocardium from the left ventricular cavity. ⋯ Six months after PMR, the majority of patients reported significant improvement of clinical symptoms (CCS class at baseline: 3.3 +/- 0.4; after 6 months: 1.6 +/- 0.9) (p < 0.001) and an increased exercise capacity (baseline: 349 +/- 138 s; after 6 months: 470 +/- 193 s) (p < 0.05); however, thallium scintigraphy failed to show increased perfusion in the PMR treated regions. PMR seems to be a safe and feasible new therapeutic option for patients with refractory angina pectoris due to end-stage coronary artery disease. The first results indicate improvement of clinical symptoms and increased exercise capacity; evidence of increased perfusion in the laser-treated regions is still lacking.
-
The molecular genetic background of inherited cardiac arrhythmias has only recently been uncovered. This late development in comparison to other inherited cardiac disorders has partly been due to the high mortality and early disease onset of these arrhythmias resulting in mostly small nucleus families. Thus, traditional genetic linkage studies, which are based on the genetic information obtained from large multi-generation families, were made difficult. ⋯ The reduced penetrance and variable expressivity associated with the LQT mutations remain still to be explained. First insights into the complex actions of mutations are being extracted, from expression data; these preliminary results may lead to potential implications for a specific (gene-site directed) therapy. This paper discusses the current data on molecular genetics and genotype-phenotype correlations in LQT syndrome and related disorders and the potential implications for diagnosis and treatment.
-
Antiarrhythmic drugs can be divided into four Vaughan Williams classes (I-IV) according to defined electrophysiological effects on the myocardium. Thus, the Vaughan Williams classification also coincides with the main myocardial targets of the antiarrhythmics, i.e., myocardial sodium-, potassium-, and calcium-channels or beta-adrenergic receptors. A more detailed characterization which is also based on the myocardial targets of a drug is given by the "Sicilian Gambit" approach of classification. ⋯ Class-III substances inhibiting the slowly activating IKs component are currently under investigation and are expected to show a direct rate dependence. Experimental data available so far point to an action potential prolonging effect at least independent of rate. However, it is uncertain whether proarrhythmic effects can be thus avoided, especially in light of the fact that one form of congenital QT syndrome (LQT1) seems to be linked to dysfunction of the IKs-channel.