A 68-year-old male patient was referred because of an irregular heart rhythm. The electrocardiogram (Fig. 1) showed sinus bradycardia with interpolated premature ventricular complexes (PVCs) occurring in a trigeminal pattern. There are two interesting observations in Figure 1. First, there is an alternating pattern of P-P intervals, with intervals of 1,320–1,340 ms whenever there is a PVC betwe...

Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in conscious cats and spontaneous contraction in decerebrate cats. The purpose of this study was to examine whether central command attenuates the sensitivity of the carotid sinus baroreceptor-HR reflex at the onset of spontaneous, f...

In IO patients with severe myocardial infarction and left ventricular failure, bretylium tosylate was used in the treatment of ventricular arrhythmias which had proved refractory to lignocaine and procainamide; 6 cases had also failed to respond to phenytoin. In 7 patients stable sinus rhythm was achieved and 5 of these survived to leave hospital. For the period during which bretylium was used,...

Directly measured sinoatrial conduction time was compared with sinoatrial conduction time assessed simultaneously by the single premature atrial stimulus technique in 59 patients: 20 with normal sinus function, 35 with sinus dysfunction, and four with sinus bradycardia but negative indirect methods. In patients with normal sinus function direct sinoatrial conduction time was 102.5 +/- 34 ms (me...

Purpose. To report the resolution of bradycardia encountered during transradial cardiac catheterization through the catheter pullback technique in two cases. Case Report. A 62-year-old male and an 81-year-old male underwent coronary angiogram to evaluate for coronary artery disease and as a result of positive stress test, respectively. Upon engagement of the FL 3.5 catheter into the ascending a...

Data based on experience of Regional Toxicological Centre in Poznań shown that most of patients self-poisoned with calcium channel blockers were cases of verapamil overdose (41 among 50 patients treated during years 1994-1999). Verapamil's greatest toxic effect is on the conduction system, with depression of the sinus node and of conduction through the atrioventricular node, but it also causes ...

The ECG (electrocardiography) shows a sinus bradycardia of 42 beats/min, a horizontal electrical heart axis and a narrow QRS complex. The second to fourth QRS complex is preceded by a P wave with a variation in the PQ time. The PQ time in the second QRS complex is 220 ms, in the third 200 ms and the fourth 140 ms. No P wave precedes the fifth QRS complex. In the sixth QRS complex, the P wave is...

BACKGROUND Dexmedetomidine (DEX) is an alpha2-adrenergic agonist that is approved by the Food and Drug Administration for short-term (<24 h) sedation in adults. It is not approved for use in children. Nevertheless, the use of DEX for sedation and anesthesia in infants and children appears to be increasing. There are some concerns regarding the hemodynamic effects of the drug, including bradycar...

The pacemaker cells of the cardiac sinoatrial node (SAN) are essential for normal automaticity. Dysfunction in pacemaking results human dysfunction (SND). SND more generally occurs elderly population and is associated with impaired function causing abnormal heart rhythm. Individuals have a variety symptoms including sinus bradycardia, arrest, SAN block, bradycardia/tachycardia syndrome, syncope...