QT-Related Rate-Responsive Pacing During Acute Myocardial Infarction

We studied the findings in a patient who had a TX 915 pacemaker and who was suffering from an acute inferior myocardial infarction. On admission, we observed pacing at the upper rate limit due to excessive adrenergic tone. Shortly thereafter a strong vagal reaction occurred, and the pacing rate fell back to the lower rate limit. This condition was improved with atropine. Conclusions: (1) In the described condition the TX pacemaker behaved in a very "physiological" fashion; (2) Sudden strong cholinergic activity lengthened the QT interval; (3) Programming of a steep slope must be avoided in coronary artery disease; (4) Stimulus-T-wave intervals at maximal adrenergic and cholinergic stimulation should be taken into account when programming the slope and the T-wave sensing window.     

Atrial Pacing via Unilateral Persistent Left Superior Vena Cava

A patient who suffered from sinus node dysfunction and automatic atrial tachycardias underwent pacemaker implantation during which time a unilateral left superior vena cava was found. Despite the known difficulties in using this venous route, it was possible to place a transvenous endocardial screw-in lead in a stable position in the lower lateral wall of the right atrium.     

Temazepam as premedication in elderly patients

One hundred and forty-five men were randomly allocated on a double-blind basis to receive either temazepam 20 mg, diazepam 10 mg or placebo as premedication. Temazepam produced more sedation than either diazepam or placebo. Postoperative recovery was assessed by a simple visuo-motor co-ordination test and was best in the placebo group. Two hours into recovery, temazepam patients could almost match their baseline performance whereas the performance of the diazepam patients was still significantly worse than pre-operatively. Temazepam is suggested as a suitable premedicant for elderly patients undergoing minor surgery.     

The Minimally Invasive Surgical Approach: A Critical Reappraisal

The use of minimally invasive techniques for cardiac surgery procedures has increased in the last 5 years. The term minimally invasive is used to describe cardiac procedures performed through a small incision or heart surgery performed without cardiopulmonary bypass. A review of the minimally invasive heart surgery literature is presented. According to the literature coronary bypass grafting without cardiopulmonary bypass can be carried out with similar early and mid-term results when compared to coronary bypass grafting with cardiopulmonary bypass. The same is true for LIMA to LAD bypass grafting performed through a lateral mini-thoracotomy. Controversial results are reported regarding morbidity after aortic and mitral valve surgery operated through a mini-incision. Some report less postoperative pain, earlier mobilization, shorter hospital stays, and lower costs. Others did not find any difference between full sternotomy and mini-incisions except a better cosmetic outcome. According to the literature there is no proven advantage of performing open heart surgery minimally invasively except in special situations, such as reoperation or polymorbid patients.     

Hepatitis B and C genotyping: methodologies and implications for patient management

Abstract   The spontaneous tendency of the hepatitis B virus (HBV) and hepatitis C virus (HCV) to mutate has led in both cases to the emergence of distinct viral genotypes with uneven geographic distributions. Numerous studies point to differential impacts of these genotypes on the course of chronic liver disease and response to treatment with currently approved drugs. HCV genotype plays a pivotal role in determining an individual's response to treatment. Evidence is also accumulating that HBV genotypes influence HBeAg seroconversion rates, the natural history and severity of chronic HBV liver disease, and the development of antiviral drug-resistance and precore/core promoter mutational patterns—all of which have an impact on disease prognosis and patient management. An overview of HBV and HCV genotypes, diagnostic methodologies for their determination, and the clinical relevance of genotypes for patient management is presented.     

Percutaneous arterial cannulation in children

For percutaneous arterial monitoring in children, the Medicut (polypropylene) is an appropriate choice of cannula. Morbidity associated with its use is low. We studied blood flow and clinical signs relating to 70 arterial cannulations in 62 patients. In the few patients exhibiting flow disturbances either whilst the cannula was in situ or following decannulation, we observed no associated clinical signs of vascular insufficiency of the forearm, wrist or digits. Also, most patients showed normal, antegrade blood flow past the cannula in situ and following decannulation. Eight patients showed retrograde flow which, in six cases, spontaneously reverted to normal whilst the child was still in hospital. The results of this study increased our confidence in the appropriateness, safety and ease of use of these polypropylene cannulae in children where peripheral arterial vessel diameters are small.