http://medicalxpress.com/ en-us Medical Xpress internet news portal provides the latest news on Health and Medicine. The heart's regular rhythm is crucial to the delivery of oxygenated blood and nutrients to all the organs of the body. It is regulated by a bundle of cells called "the pacemaker," which use electrical signals to set the pace of the heart. Dysfunction in this mechanism can lead to an irregular heartbeat, known as arrhythmia, and often necessitates the implantation of an artificial pacemaker. http://medicalxpress.com/news/2013-06-team-unknown-channel-heart-illuminate.html Cardiology Tue, 11 Jun 2013 11:53:48 EST news290170389 Having diabetes doubles a person's risk of dying after a heart attack, but the reason for the increased risk is not clear. A new University of Iowa study suggests the link may lie in the over-activation of an important heart enzyme, which leads to death of pacemaker cells in the heart, abnormal heart rhythm, and increased risk of sudden death in diabetic mice following a heart attack. http://medicalxpress.com/news/2013-02-link-diabetes-heart-death.html Cardiology Fri, 15 Feb 2013 13:30:01 EST news280156983 Cedars-Sinai Heart Institute researchers have reprogrammed ordinary heart cells to become exact replicas of highly specialized pacemaker cells by injecting a single gene (Tbx18)–a major step forward in the decade-long search for a biological therapy to correct erratic and failing heartbeats. http://medicalxpress.com/news/2012-12-ordinary-heart-cells-biological-pacemakers.html Medical research Sun, 16 Dec 2012 13:00:16 EST news274884285 The heartbeat is the result of rhythmic contractions of the heart muscle, which are in turn regulated by electrical signals called action potentials. Action potentials result from the controlled flow of ions into heart muscle cells (depolarization) through channels in their membranes, and are followed by a compensating reverse ion current (repolarization), which restores the original state. If the duration of the repolarization phase is not just right, the risk of ventricular arrhythmia and sudden cardiac death increases significantly. http://medicalxpress.com/news/2011-09-rhythm-ion-channels-heart.html Cardiology Fri, 09 Sep 2011 09:45:51 EST news234780336 An international team of molecular scientists have discovered that star ascidians, also known as sea squirts, have pacemaker cells similar to that of the human heart. The research, published in the JEZ A: Ecological Genetics and Physiology, may offer a new insight into the early evolution of the heart as star ascidians are one of the closest related invertebrates to mammals. http://medicalxpress.com/news/2011-08-sea-squirt-pacemaker-insight-evolution.html Medical research Tue, 02 Aug 2011 10:40:07 EST news231498505 Caffeine reduces muscle activity in the Fallopian tubes that carry eggs from a woman's ovaries to her womb. "Our experiments were conducted in mice, but this finding goes a long way towards explaining why drinking caffeinated drinks can reduce a woman's chance of becoming pregnant," says Sean Ward, professor of physiology and cell biology, at the University of Nevada School of Medicine, who conducted the study. http://medicalxpress.com/news/2011-07-caffeine-consumption-female-infertility-link.html Medical research Wed, 20 Jul 2011 12:46:44 EST news230384776 Caffeine reduces muscle activity in the Fallopian tubes that carry eggs from a woman's ovaries to her womb. "Our experiments were conducted in mice, but this finding goes a long way towards explaining why drinking caffeinated drinks can reduce a woman's chance of becoming pregnant," says Professor Sean Ward from the University of Nevada School of Medicine, Reno, USA. Ward's study is published today in the British Journal of Pharmacology. http://medicalxpress.com/news/2011-05-caffeine-fertility-women.html Medical research Thu, 26 May 2011 03:21:09 EST news225598849