Dr. Usman's Cardiology Notes

  🧠 Imagine remembering every single day of your life — with every emotion intact. One teen can.  Meet TL, a teenager in France with hyperthymesia — a rare condition that gives her near-perfect autobiographical memory. She can recall every day of her life in extraordinary detail, from sights and sounds to the emotions she felt. In her mind, these memories are stored in a vivid “white room,” a mental library where every toy, book, and photograph she’s ever owned is neatly organized.  Even painful moments are compartmentalized — her grandfather’s death, for instance, is sealed in a mental chest. But TL’s ability doesn’t stop with the past.  She can also “pre-experience” imagined future events, feeling a strange déjà vu for things that haven’t yet occurred.  Scientists studying her unique mind hope her case will help unlock deeper understanding of how the brain processes memory, imagination, and identity — the essence of what makes us human. Source: 🔹 “Autobiogra...

  🫀 Mechanism of Action of Adenosine – Explained Clearly Adenosine is one of the most fascinating drugs in cardiology — a molecule that literally stops the heart for a moment to save it. Despite its short half-life (less than 10 seconds!), its physiological and therapeutic effects are profound. Let’s break down how this tiny nucleoside exerts such dramatic actions. --- 💊 What is Adenosine? Adenosine is an endogenous purine nucleoside — a naturally occurring compound in the body derived from the breakdown of ATP (adenosine triphosphate). It plays roles in energy transfer, cell signaling, and modulation of cardiac and vascular function. Clinically, adenosine is used mainly for: Termination of paroxysmal supraventricular tachycardia (PSVT) Diagnosis of tachyarrhythmias during electrophysiological testing Assessment of coronary blood flow reserve in stress testing --- ⚙️ Mechanism of Action Adenosine acts through specific adenosine receptors located on cardiac and vascular tissues. T...

𝗗𝗶𝗴𝗼𝘅𝗶𝗻 — 𝗔 𝗖𝗹𝗮𝘀𝘀𝗶𝗰 𝗗𝗿𝘂𝗴 𝘄𝗶𝘁𝗵 𝗮 𝗧𝗶𝗺𝗲𝗹𝗲𝘀𝘀 𝗠𝗲𝗰𝗵𝗮𝗻𝗶𝘀𝗺 Digoxin, one of the oldest cardiac drugs still in use today, continues to play a critical role in the management of heart failure and atrial fibrillation. Despite newer agents, digoxin remains unique because of its dual action — both inotropic and chronotropic. Let’s dive into its mechanism of action, step by step. --- 🔬 𝗠𝗼𝗹𝗲𝗰𝘂𝗹𝗮𝗿 𝗧𝗮𝗿𝗴𝗲𝘁: 𝗡𝗮⁺/𝗞⁺-𝗔𝗧𝗣𝗮𝘀𝗲 𝗜𝗻𝗵𝗶𝗯𝗶𝘁𝗶𝗼𝗻 At the core of digoxin’s mechanism lies its inhibition of the Na⁺/K⁺-ATPase pump, located on the cardiac cell membrane. Normally, this pump extrudes 3 Na⁺ ions out of the cell and brings in 2 K⁺ ions, maintaining the electrochemical gradient. Digoxin binds to the extracellular domain of this pump, inhibiting its activity. This causes intracellular Na⁺ concentration to rise. This simple change triggers a cascade of ionic effects that ultimately increase cardiac contractility. --- ⚙️ 𝗦𝘁𝗲𝗽-𝗯𝘆-𝗦𝘁𝗲...

The Silent Surge: How Micro-plastics Are Invading Our Bodies — What You Need to Know & How to Protect Yourself Key Concept: Explore how micro-plastics are finding their way into human tissues, the emerging health concerns, and practical steps you can take today to reduce exposure and safeguard your well-being. --- Introduction We live in a world surrounded by plastic — packaging, bottles, containers, even clothes with synthetic fibres. But what if tiny plastic fragments, invisible to the naked eye, are on the move: entering our bodies, circulating in our tissues, and quietly affecting our health? This is the emerging issue of micro-plastics: plastic particles smaller than 5 millimetres (and many much smaller) that are now showing up in oceans, soils, food chains — and according to recent studies — in human tissues too. For many people this topic still floats below the public radar, yet searches are rising, and the content online remains thin. This is a perfect opportunity for infor...

The Future of Heart Health: How AI is Detecting Heart Disease Before Symptoms Appear A New Era of Prevention in Cardiology For decades, heart disease has remained the leading cause of death worldwide — often striking silently until it’s too late. But a revolution is quietly taking place: Artificial Intelligence (AI) is learning to detect cardiovascular disease before it even shows symptoms. This breakthrough could transform how we prevent heart attacks, strokes, and sudden cardiac deaths — shifting medicine from reactive to predictive care. What Is AI-Driven Cardiac Screening? AI algorithms are trained on thousands (sometimes millions) of ECGs, echocardiograms, and cardiac MRI scans. These systems learn subtle patterns that even the most experienced clinicians might miss. For example: AI can detect asymptomatic left ventricular dysfunction on a standard ECG. It can predict future heart failure risk years in advance. Some models can even analyze your voice or facial blood flow patterns ...

  Hidden Therapies: How Drug Repurposing Could Revolutionize Treatment of Rare Diseases Key Concept: Discover how existing medications are being repurposed to treat rare diseases, bridging the treatment gap and bringing new hope to millions worldwide. Learn how this overlooked field could reshape modern medicine. --- Introduction: A New Hope for Rare Diseases Imagine hearing that your condition has no approved treatment. For millions of people living with rare diseases, that phrase is heartbreakingly familiar. There are over 7,000 rare diseases known today — but only a small fraction have any effective therapy available. While pharmaceutical innovation races ahead for common illnesses, patients with rare conditions are often left behind. But now, a powerful idea is transforming that outlook: drug repurposing — finding new uses for existing drugs. Instead of waiting years for a new compound to be discovered, what if we could use a medicine already sitting on the pharmacy shelf? This...

Closed Loop Stimulation (CLS) is an advanced pacing algorithm used in modern pacemakers — particularly by Biotronik — that allows the device to continuously adapt the heart rate according to the patient’s physiological needs, not just activity level. Here’s a breakdown 👇 --- 🔹 Concept Traditional rate-responsive pacemakers use sensors like: Accelerometers (detect body motion) Minute ventilation sensors (detect breathing rate) However, these only respond to external activity, not to emotional stress or internal changes (like pain, anxiety, or standing up suddenly). CLS, on the other hand, creates a closed feedback loop between the heart’s own signals and the pacemaker’s pacing rate. --- 🔹 How It Works 1. Sensing intracardiac impedance: The pacemaker continuously measures right ventricular impedance during each heartbeat. This impedance reflects myocardial contractility — which changes with autonomic nervous system activity (sympathetic and parasympathetic tone). 2. Interpreting contr...