Types of Ventricular Tachycardia
Three or more ventricular beats in a row at a rate above 100 per minute is termed ventricular tachycardia. Ventricular tachycardia lasting more 30 seconds or requiring termination earlier due to hemodynamic compromise is called sustained ventricular tachycardia. Non sustained ventricular tachycardia is one which lasts less than 30 seconds without hemodynamic compromise.
Based on the morphology, ventricular tachycardia can be classifed into monomorphic in which all beats have same morphology on ECG in a given lead and polymorphic in which there is beat to beat variation.
Polymorphic ventricular tachycardia with QT interval ...
Source: Cardiophile MD - April 23, 2024 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
L-type and T-type Calcium Channels
Calcium channels in the heart muscle are of two types: L-type (ICa-L) and T-type (ICa-T). Both these are voltage gated calcium channels. L-type channels are involved in the myocardial contraction while T-type channels are involved in impulse generation and conduction. The calcium channels are located in the plasma membrane and are protein complexes that are voltage gated to regulate entry of calcium ions into the cell.
Phase 2 or plateau phase of myocardial action potential is featured by influx of calcium ions through L-type calcium channels (ICa-L). In addition to myocardial cells, L-type calcium channels are important i...
Source: Cardiophile MD - April 21, 2024 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Ventricular Tachycardia Management
Ventricular tachycardia is a potentially life threatening cardiac arrhythmia. If the rate is very fast, hemodynamic deterioration can occur rapidly. On the ECG, ventricular tachycardia can be defined as three or more ventricular ectopic beats occurring in a sequence at a rate more than 100 per minute.
Ventricular tachycardia which gets spontaneously terminated within 30 seconds is called non sustained ventricular tachycardia (NSVT) . Sustained ventricular tachycardia is one which does not get spontaneously terminated within 30 seconds or needs cardioversion before that due to hemodynamic compromise.
Based on the morphology...
Source: Cardiophile MD - April 17, 2024 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Assessment of LV Diastolic Function by Echo in SR and AF
Echocardiographic assessment of left ventricular diastolic function with special reference on diastolic function assessment in atrial fibrillation.
Though there are several parameters for evaluation of left ventricular diastolic function by echocardiography, the most commonly used are the pulsed Doppler mitral E/A ratio and tissue Doppler mitral E/e’ ratio.
Some of the other useful parameters are mitral E velocity deceleration time, changes in mitral inflow with Valsalva maneuver, mitral L velocity, isovolumic relaxation time, left atrial maximum volume index, pulmonary vein systolic/diastolic velocity ratio, color M-mod...
Source: Cardiophile MD - April 15, 2024 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
Palpitations and presyncope in a 40-something
Discussion: Putting all of the information together this patient is most likely suffering from arrhythmogenic cardiomyopathy (AC) better known as ARVC. The medical hx is typical, with sudden onset tachydysrhythmia during physical exertion. It is not uncommon for the initial presentation to be sudden cardiac death (SCD). In fact it is one of the leading causes of SCD in people age less than 40 years. Thus it is very important to identify this disorder. AC is a disease in which myocardium is replaced by fibrofatty tissue. This usually and predominantly affects the RV free wall and apical regions, but it can affect the left v...
Source: Dr. Smith's ECG Blog - March 24, 2024 Category: Cardiology Authors: Magnus Nossen Source Type: blogs
Why ICDs are less effective in Non Ischemic DCM ?
We wish, our understanding about cardiac contractile physiology is deep and nearly complete. Heart is an irreversibly coupled electro-mechanical organ , right from the fetal days until the final heart beat. In myocardial pathology, the genesis and sustainability of ventricular arrhythmia are intricately related to the degree of LV dysfunction of any cause.
SCD is the leading cause of mortality in heart failure. Tackling SCD was in God’s domain, until the brilliance of Dr. Michel Mirowski shrunk the defibrillator and implanted it under the chest in 1980. (Dr. MM’s s a unique and inspiring story, from Poland a...
Source: Dr.S.Venkatesan MD - February 20, 2024 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized crt device crt-p vs crt-d danish trial ischemic dcm madit trial non ischemic dcm Source Type: blogs
Potential options for reducing cardiotoxicity of anthracyclines
What are the potential options for reducing cardiotoxicity of anthracyclines?
Anthracyclines are an important group of medications useful in the treatment of solid tumours and hematological malignancies. An important limitation is their potential cardiotoxicity which can cause heart failure at varying time intervals, even decades later. Some methods which have been used to prevent cardiotoxicity are longer infusion times, use of liposomal preparations, dexrazoxane, beta blockers and renin-angiotensin system inhibitors, all with different success rates. These strategies have not been universally accepted as useful modalitie...
Source: Cardiophile MD - February 18, 2024 Category: Cardiology Authors: Johnson Francis Tags: General Cardiology Source Type: blogs
A young woman with palpitations. What med is she on? With what medication is she non-compliant? What management?
Written by Pendell MeyersA woman in her 20s with connective tissue disorder and history of aortic root and valve repair presented with palpitations. Here is her triage ECG: What do you think?Atrial flutter with 2:1 conduction. The atrial flutter rate is approximately 200 bpm, with 2:1 AV conduction resulting in ventricular rate almost exactly 100 bpm. The fact that the atrial flutter rate is 200 bpm (rather than more typical adult rate of ~300 bpm) suggests that the patient must have one or both of the following:1) enlarged atria ( " bigger race track " )2) sodium channel blockade ( " slower race car "...
Source: Dr. Smith's ECG Blog - December 24, 2023 Category: Cardiology Authors: Pendell Source Type: blogs
Continuous prolonged generalized weakness, lightheadedness, and presyncope. What might you suspect from the ECG?
A young man presented with continuous prolonged generalized weakness, lightheadedness, and presyncope. There was some dyspnea but no chest pain. Here is his ECG. This shows LVH, with high voltage.LVH can have very thick-walled ventricles and a correspondingly small LV cavity. LVH is a common etiology of heart failure with preserved ejection fraction, as it may results in a stiff ventricle with poor diastolic relaxation.See this articles: Heart Failure with Preserved Ejection Fraction (NEJM review)One etiology of LVH on the ECG is Hypertrophic Cardiolmyopathy (HOCM), and sometimes ECGs in pa...
Source: Dr. Smith's ECG Blog - October 28, 2023 Category: Cardiology Authors: Steve Smith Source Type: blogs
Rate vs Rhythm Control in Atrial Fibrillation
Rate vs rhythm control as a management strategy in atrial fibrillation has been a long standing topic for debate. Though at one look rhythm control would appear to be the ideal strategy, long term adverse effects of the currently available medications for rhythm control is the often cited down side. AFFIRM [1] and RACE [2] trials were the main reason for the debate as they failed to show any benefit for the rhythm control strategy. AF-CHF trial in those with AF and congestive heart failure also failed to show any advantage for the rhythm control strategy [3]. But there have been important criticisms as well [4]. In AFFIRM...
Source: Cardiophile MD - October 26, 2023 Category: Cardiology Authors: Johnson Francis Tags: ECG / Electrophysiology General Cardiology Source Type: blogs
Vasodilators For High Blood Pressure: Types, Side Effects, Drug Interactions
Conclusion
In summary, vasodilators play a pivotal role in managing cardiovascular conditions, including hypertension, which is rapidly becoming a global health concern.
By expanding the body’s blood vessels, these unique medications can improve blood flow and decrease the pressure exerted by the heart, thereby providing relief to numerous patients worldwide.
Their applications are diverse, extending beyond hypertension to conditions like angina, heart failure, and even erectile dysfunction.
However, these medications should be taken carefully and always under the supervision of a doctor due to the potent...
Source: The EMT Spot - July 27, 2023 Category: Emergency Medicine Authors: Michael Rotman, MD, FRCPC, PhD Tags: Blood Pressure Source Type: blogs
Central Agonists For High Blood Pressure: Types, Side Effects, Drug Interactions
Conclusion
In summary, central agonists, a notable class of hypertension medications, offer an alternative modality when other first-line antihypertensive treatments fail to show desired results or cause intolerable side effects.
They operate via a unique neurocentric mechanism that primarily functions centrally in the brain, impacting blood pressure regulation by decreasing systemic arterial pressure and heart rate.
Despite their potential side effects and potential for interactions with other drugs, their therapeutic utility in the context of hypertension management remains undiminished.
Moreover, certain cen...
Source: The EMT Spot - July 27, 2023 Category: Emergency Medicine Authors: Michael Rotman, MD, FRCPC, PhD Tags: Blood Pressure Source Type: blogs
Handling Heat On Blood Pressure Medication: Your Summer Health Guide
Conclusion
Summing it up, individuals taking blood pressure medication must be cautious during the hot weather season. Heat exposure can significantly impact blood pressure and may amplify the effects of medication, leading to potentially harmful health conditions.
These risks, however, can be managed with the right precautions such as staying hydrated, dressing appropriately, and planning outdoor activities during cooler times of the day.
Importantly, each person’s response to heat and medication varies. Hence, a one-size-fits-all approach isn’t ideal. Your healthcare provider is an invaluable resourc...
Source: The EMT Spot - July 26, 2023 Category: Emergency Medicine Authors: Michael Rotman, MD, FRCPC, PhD Tags: Blood Pressure Source Type: blogs
Beta-Blockers For High Blood Pressure: Types, Side Effects, Drug Interactions
Conclusion
In conclusion, beta-blockers serve as an indispensable tool in the realm of modern medical treatment, particularly in managing a broad range of cardiovascular conditions.
Their unique mechanism of action, which includes decreasing heart rate and blood pressure, confers a significant cardio-protective effect.
This, combined with their versatility and the extensive clinical experience with their use, has cemented beta-blockers as a first-line treatment for various conditions, from hypertension and heart failure to anxiety and migraines.
Although beta-blockers present unique benefits, it’s crucial...
Source: The EMT Spot - July 24, 2023 Category: Emergency Medicine Authors: Michael Rotman, MD, FRCPC, PhD Tags: Blood Pressure Source Type: blogs
Calcium-Channel Blockers For High Blood Pressure: Types, Side Effects, Drug Interactions
Conclusion
In a nutshell, calcium-channel blockers are a valuable tool in the medical arsenal for treating a range of cardiovascular conditions.
By inhibiting calcium’s entry into the heart and blood vessel cells, these drugs induce blood vessel dilation and relaxation, reducing blood pressure.
Their unique properties and effectiveness make them especially suitable for groups like older adults and people of African descent, and those with conditions like angina, certain arrhythmias, and Raynaud’s disease.
Even with the possibility of side effects and drug interactions, calcium-channel blockers are g...
Source: The EMT Spot - July 24, 2023 Category: Emergency Medicine Authors: Michael Rotman, MD, FRCPC, PhD Tags: Blood Pressure Source Type: blogs
