A 16-year-old male presents to the cardiologist after passing out during a basketball practice. An echocardiogram confirmed the diagnosis of hypertrophic cardiomyopathy. The cardiologist advises that a pacemaker must be implanted to prevent any further complications and states the player cannot play basketball anymore. Unfortunately, the coach objects to sidelining the player since a big game against their rivals is next week. The coach asks if the pacemaker can be implanted after the game, which of the following steps should the physician take?

Recommend to the legal guardian that the player stop playing and have the procedure performed

Postpone the procedure so the patient can play

Allow the patient to play and schedule a follow up after the game

Perform the procedure immediately so that both the physician and coach's wishes may be fulfilled

Allow the patient to make the decision regarding his health

A previously healthy 20-year-old man is brought to the emergency department 15 minutes after collapsing while playing basketball. He has no history of serious illness. On arrival, there is no palpable pulse or respiratory effort observed. He is declared dead. The family agrees to an autopsy. Cardiac workup prior to this patient's death would most likely have shown which of the following findings?

Systolic anterior motion of the mitral valve

Narrowing of the left main coronary artery

A 19-year-old woman is brought to the emergency department by ambulance 30 minutes after her neighbor found her unconscious on a running trail. Her neighbor reports that she has been training for a marathon since the beginning of the summer. She is alert and oriented but becomes irritable when realizing that she is at a hospital and refuses to answer questions. She appears tired. She is 174 cm (5 ft 7 in) tall and weighs 51 kg (112 lb). Her temperature is 35.5°C (96°F), pulse is 44/min, respirations are 20/min, and blood pressure is 84/48 mm Hg. Examination shows dry, scaly skin and dry mucous membranes. Cardiopulmonary examination shows a high-frequency, mid-to-late systolic murmur that is heard best at the apex. Her hemoglobin concentration is 11.9 g/dL. Which of the following is the most likely diagnosis?

Hypertrophic obstructive cardiomyopathy

You are the team physician for an NBA basketball team. On the morning of an important playoff game, an EKG of a star player, Mr. P, shows findings suspicious for hypertrophic cardiomyopathy (HCM). Mr. P is an otherwise healthy, fit, professional athlete. The playoff game that night is the most important of Mr. P's career. When you inform the coach that you are thinking of restricting Mr. P's participation, he threatens to fire you. Later that day you receive a phone call from the owner of the team threatening a lawsuit should you restrict Mr. P's ability to play. Mr. P states that he will be playing in the game "if it's the last thing I do." Which of the following is the most appropriate next step?

Educate Mr. P about the risks of HCM and restrict him from playing pending cardiology evaluation

Allow Mr. P to play against medical advice

Consult with a psychiatrist to have Mr. P committed

Call the police and have Mr. P arrested

Schedule a repeat EKG for the following morning

A 72-year-old man is taken to the emergency room after losing consciousness. According to his wife, he suddenly complained of fluttering in his chest, lightheadedness, and profuse sweating while walking to the grocery store. He then turned gray, lost consciousness, and collapsed onto the ground. His medical history is significant for a prior anterior wall myocardial infarction 2 years ago that was complicated by severe left ventricular systolic dysfunction. His blood pressure is 80/50 mm Hg, the temperature is 36.7°C (98.0°F), and the carotid pulse is not palpable. An ECG was obtained and the results are shown in the picture. Cardiopulmonary resuscitation is initiated and the patient is cardioverted to sinus rhythm with an external defibrillator. The patient regains consciousness and states there was no antecedent chest discomfort. Cardiac enzymes are negative and serum electrolytes are normal. Which of the following is the best next step for this patient?

Temporary or permanent cardiac pacing

A previously healthy 21-year-old man is brought to the emergency department for the evaluation of an episode of unconsciousness that suddenly happened while playing football 30 minutes ago. He was not shaking and regained consciousness after about 30 seconds. Over the past three months, the patient has had several episodes of shortness of breath while exercising as well as sensations of a racing heart. He does not smoke or drink alcohol. He takes no medications. His vital signs are within normal limits. On mental status examination, he is oriented to person, place, and time. Cardiac examination shows a systolic ejection murmur that increases with valsalva maneuver and standing and an S4 gallop. The remainder of the examination shows no abnormalities. An ECG shows a deep S wave in lead V1 and tall R waves in leads V5 and V6. Echocardiography is most likely to show which of the following findings?

Abnormal movement of the mitral valve

Mitral valve leaflet thickening ≥ 5 mm

Reduced left ventricular ejection fraction

Symmetric left ventricular wall thickening

A 22-year-old medical student presents to a community health center due to an episode of loss of consciousness 3 days ago. She also has a history of multiple episodes of dizziness in the last year. These episodes almost always occur when she is observing surgery in the operating room. She describes her dizziness as a feeling of lightheadedness, warmth, excessive sweating, and palpitations. She feels that she will fall down if she stood longer and usually sits on the floor or leaves the room until the feeling subsides. Three days ago, she collapsed while observing an open cholecystectomy but regained consciousness after a few seconds. Once she regained consciousness, she was pale and sweating excessively. Her medical history is significant for migraines, but she is not on prophylactic therapy. Her younger brother has cerebral palsy, and her uncle had a sudden death at the age of 25. Her blood pressure is 120/80 mm Hg when lying down and 118/80 mm Hg when in a standing position. The rest of the physical examination is within normal limits. What is the next best step in the management of this patient?

Psychiatric evaluation for anxiety

Sudden cardiac death for USMLE Step 1: High-Yield Internal Medicine Lessons

SCD Basics - The Final Countdown

Definition: Unexpected death from cardiac causes, often within 1 hour of symptom onset in a person without a previously known fatal condition.
Etiology (Adults):
- >80% due to Coronary Artery Disease (CAD), typically from an acute plaque rupture leading to ischemia.
- Other causes: Cardiomyopathies (HOCM, DCM), channelopathies (e.g., Long QT, Brugada syndrome), and valvular heart disease.
Terminal Rhythm: Ventricular Fibrillation (VF) or pulseless Ventricular Tachycardia (pVT) is the final common pathway in most cases.

ECG: Ventricular Fibrillation

⭐ In young athletes (<35 years), the most common cause of SCD is Hypertrophic Cardiomyopathy (HOCM).

Etiologies & Causes - Heart's Short Circuit

Ischemic Heart Disease (>80% of cases)
- Coronary Artery Disease (CAD) is the leading cause, creating a scar-based substrate for re-entrant ventricular tachycardia (VT).
Non-Ischemic Cardiomyopathies
- Structural Heart Disease:
  - Hypertrophic Cardiomyopathy (HCM)
  - Dilated Cardiomyopathy (DCM)
  - Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
- Primary Electrical Disorders (Channelopathies):
  - Long QT Syndrome (LQTS)
  - Brugada Syndrome
  - Catecholaminergic Polymorphic VT (CPVT)

⭐ In young athletes (<35 years), the most common cause of SCD is hypertrophic cardiomyopathy (HCM).

Risk Stratification - Dodging Danger

Primary Prevention (No prior SCD event):
- Core metric: Left Ventricular Ejection Fraction (LVEF).
- LVEF ≤ 35% despite optimal medical therapy (OMT) is a class I indication for an Implantable Cardioverter-Defibrillator (ICD).
  - Ischemic (Post-MI): Wait ≥ 40 days post-event.
  - Non-ischemic: Wait ≥ 3 months after OMT optimization.
Secondary Prevention (SCD survivor):
- History of VF or hemodynamically unstable VT arrest.
- Strong indication for ICD if the cause was not transient or reversible.

⭐ For primary prevention in post-MI patients, ICD implantation is deferred for at least 40 days to allow for potential LV function recovery. This waiting period is a common exam point.

ICD Risk Stratification for Primary Prevention

Prevention & ICDs - The Shocking Solution

Primary Prevention: Aims to prevent SCD in high-risk individuals who have not yet had a life-threatening arrhythmia.
- Core Indication: Left Ventricular Ejection Fraction (LVEF) ≤ 35% due to prior MI (at least 40 days post-MI) or non-ischemic cardiomyopathy (NICM).
- Prerequisite: Patient must be on optimal medical therapy (OMT) for at least 3 months with reasonable survival expectancy (>1 year).
Secondary Prevention: For survivors of SCD.
- Indication: Documented history of VF arrest or hemodynamically unstable sustained VT.

⭐ In primary prevention for NICM, an ICD is indicated if LVEF is ≤ 35% and NYHA class II-III symptoms persist despite >3 months of OMT (SCD-HeFT trial).

Chest X-ray: Implantable Cardioverter-Defibrillator (ICD)

Most common cause of SCD is ventricular fibrillation (VF), typically from underlying coronary artery disease.

Key predictors include prior myocardial infarction and severe left ventricular dysfunction (EF < 35%).

In young athletes, the leading cause is Hypertrophic Cardiomyopathy (HCM), followed by anomalous coronary arteries.

Immediate survival depends on high-quality CPR and rapid defibrillation.

Implantable Cardioverter-Defibrillator (ICD) is the mainstay for primary and secondary prevention in high-risk patients.

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