Cardiac electrophysiology

the atrial signal, you can't see the atrial repolarization -- kind of like a flashlight turned on during the midday sun. Give yourself a pat on the back for catching its existence though. And lastly, we have the QT interval. The QT interval is not a separate section, but is a combination of the QRS complex and its following T wave. It represents the time between the start of ventricular depolarization and the end of ventricular repolarization. It is useful as a measure of the duration of repolarization. So what's your doctor looking for when she examines your ECG? To put it simply, she's looking for normal intervals and normal amplitudes in all key segments of the wave. For example: The PR interval is indicative of the movement of the cardiac impulse from the atria to the ventricles via the atrioventricular node (see The Anatomy of the Heart), which is normally between 0.12 - 0.20 sec (3 - 5 small boxes wide). If the PR interval is greater than 0.20 sec, that's an indicator that an AV block is present (see Heart Problems). The QT interval will vary depending on the heart rate, age, and gender of the patient. It increases with bradycardia (slow heartbeat) and decreases with tachycardia (rapid heartbeat). Men have shorter QT intervals (0.39 sec) than women (0.41 sec). The QT interval is also influenced by the electrolyte balance, drugs, and ischemia. Your doctor will be looking for any interval outside the norm. A QRS interval of 0.04 to 0.10 seconds -- no larger than half…

Cardiac Arrhythmia is an anomaly in the Heart which can be diagnosed with the help of Electrocardiogram (ECG) signal. ECG signal is a diagrammatic representation of the cardiac signal, which is most important biomedical signal, taken for the feature extraction. Since it is very difficult to analyse the ECG signal due to the size, noise and changes in the signal, automatic system for ECG signal processing is essential. For this, ECG signal is processed using wavelets based signal processing,…

A growing number of non-cardiac drugs have been found to delay cardiac repolarization, causing QT interval prolongation and predisposing patients to an increased risk of potentially fatal ventricular arrhythmias, known as torsade de pointes (TdP) (Letsas et al, 2007; Yap and Camm 2003; Sanguinetti and Tristani-Firouzi). These drugs include the second-generation, non-sedating antihistamines astemizole and terfenadine, withdrawn from the market in Europe and the United States (in 1997 and 1999,…

Concerning my interest in child heath and wellness, I think there is both an objective and a more emotionally-imbued reason. Detaching myself from the emotional aspects of working with and for the sake of children, I am interested in child health because children are constantly growing and developing. In respects to neuroscience, I am able to see and research neurological diseases and cognitive functions as it applies to a brain that is constantly changing. The adult brain does have some…

Elaborative Rehearsal and Cardiac Arrhythmias The process of memory is encoding, storing and retrieving information. The information is processed using visual, semantic, or acoustic ques. Maintenance and elaborative rehearsal are storage codes used to store the encoded information. Elaborative rehearsal is “elaborating” on the definition of the word using semantics, acronyms, or acoustic syllables. To adequately retrieve the information, you have encoded and stored you must use proper retrieval…

Cardiac Dysrhythmia Cardiac Dysrhythmia also known as cardiac arrhythmia is a group of of conditions where the heartbeat is irregular and or too fast or too slow. Tachycardia is known as a heart rate that is over 100 beats per minute for adults ,while Bradycardia is too slow with below 60 beats per minute. Majority of arrhythmia issues are not serious, but some predispose one to complications like heart failure or a stroke. Arrhythmia are the leading cause of sudden cardiac death, with 400,000…

how people live. In regards to the waves, it gives a visual of how a person heart rate goes up and down and to look for any normal or abnormal heart rhythm. Since the P wave is the sinoatrial node, which is the pacemaker of the heart, it is essential that the must be working at all times to be able to send the signal to the atrioventricular node that sends signals to the QRS. When that occurs the right atrium is receiving blood from the superior and inferior vena cava to pushes blood to the…

Just because you are older does not mean you are experiencing worse symptom than the younger patients. Older patients experience cardiac problems more regularly. 38.5% of people that received an icd were 70 years or older, only 7% were 80 and older. The only that your age as to do with is death (Yung et al, 2013). “For example, among those undergoing ICD implantation for prevention of cardiac arrest, 2 in every 100 patients ages 18-49 died whereas 10 in 100 died among those 80 years and older.”…

patient’s ST segment elevation is 2 mm or higher and they have “a negative T wave in right precordial leads,” this is indicative of Brugada syndrome. Another indicator of this disease would be that the electrocardiogram would show change occurring with the electrical activity of the heart and it will oftentimes be concealed. One way to fix the concealed ECG would be to conduct a sodium channel blocker. Studies were performed with several groups of people with this rare disease, and the long…

considered regular or normal. Cardiac arrest: the sudden loss of heart function, breathing and consciousness caused by abnormal or irregular heart rhythms (ex: ventricular fibrillation) Cardiomyopathy: a disease of the heart muscle (myocardium), may be acquired or hereditary Defibrillation: administration of a controlled electric shock to stop an extremely rapid, irregular heart beat (fibrillation) and restore heart rate to a normal rhythm. Determinants: elements that identify or determine the…