Cardiac Ultrasound: Getting to the heart of cardiovascular disease

Heart disease prevalence continues to climb¹,  claiming millions of lives every year and remaining the leading cause of death worldwide². Diagnosis is still challenging, creating avoidable delays between presentation and treatment³, calling for improvements to the speed and accuracy of current methods. Ultrasound – one of the most inexpensive and widely available imageing modalities – allows for direct visualisation of cardiac structure and function, representing a reasonable first step in cardiac health assessment⁴. Cardiac ultrasound is considered a first-line tool in heart disease diagnosis and management precisely because of its simplicity. Its inherent advantages – the use of harmless, painless sound waves, overall affordability, and ease of use – combine convenience with high-resolution imageing without ionising radiation, bringing returns on diagnostic information in real-time⁵.  Today’s cardiac ultrasound technology offers accurate diagnosis and enables development of treatment modalities, making it an ideal approach for frontline diagnostics and image-guided procedures.

Cardiac Imageing at the Point of Care
Although clinical application of echocardiography can be traced back to the early 1950s⁶, the emergence of portable ultrasound systems truly revolutionised its use and propelled its expansion beyond traditional settings and within medical training programmes⁷. Point-of-care ultrasound (POCUS) has become a practise-changing technology for emergent and critically ill patient care. In primary care, access to echocardiography can accelerate specialist input and implementation of disease-modifying therapy⁸, enhancing operational efficiency and improving patient outcomes. In the current health care delivery landscape, POCUS can expedite triage and diagnosis, direct consultations, and guide clinical therapy and patient disposition, significantly decreasing morbidity and mortality in critically ill patients⁹.

Indications
Noninvasive, transthoracic echocardiography (TTE) can provide detailed structural and hemodynamic information for identification of life-threatening conditions such as major valve failure, severe reduction in biventricular function, cardiac tamponade, pulmonary embolism, and aortic dissection¹⁰.  Cardiac POCUS can also aid in differentiating shock states and guiding resuscitative measures¹¹. 
 

Chest Pain - Focused cardiac ultrasound improves diagnostic specificity for evaluation of chest pain when differentials such as global cardiac dysfunction, aortic dissection, pericardial effusion, cardiac tamponade, pulmonary embolism (PE), or several primary pulmonary processes must be excluded.^{12 13 14} In the appropriate clinical setting, left ventricle (LV) wall motion abnormalities detected by ultrasound can indicate acute coronary syndrome;¹¹ RV dilation may be suggestive of PE.¹⁵

Dyspnea – Shortness of breath can have cardiac, pulmonary, or a combination of both etiologies; POCUS can help make this important distinction. Cardiac ultrasound can assess the presence of pericardial effusion¹⁶,  myocarditis, congestive heart failure, endocarditis¹⁷,  acute coronary syndrome, or valvular heart disease¹⁸.  In addition, POCUS lung ultrasound can evaluate pleural line integrity, consolidation, and pneumothorax.¹⁹  Bedside TTE has a specificity of 83% and a sensitivity of 53% for pulmonary embolism assessment²⁰  and is an adequate rule-in test for unstable patients that are unable to get other confirmatory studies.

Hypotension – Shock represents up to one-third of all intensive care unit admissions and is associated with high morbidity and in-hospital mortality.²¹  Early recognition can improve patient outcomes,²²  but traditional physical examination and hemodynamic monitoring alone cannot accurately establish circulatory failure etiology.²³  Ultrasound protocols for standardised assessment of the inferior vena cava (IVC), gross LV function, lung, and abdomen can drastically increase overall diagnostic accuracy in various patient environments,²⁴  allowing for rapid differentiation between septic, cardiogenic, hypovolemic, and obstructive shock.²⁵  In addition, POCUS enables real-time evaluation of patients' response to interventions, helping guide diagnostic procedures.¹² 

Cardiac Arrest – Approximately 90% of sudden cardiac arrest events are fatal, with 50% of victims presenting no prior symptoms or previous history of heart disease, and accounting for an estimated 325,000 deaths each year.²⁶  POCUS can assist in timely detection of reversible anatomic causes such as pericardial effusion, cardiac tamponade, tension pneumothorax, or pulmonary embolism, and identify conditions that present similarly but have opposing treatments, like asystole and fine ventricular fibrillation.²⁷ Ultrasound can also guide the application and location of force during resuscitation to elicit higher quality compression for improved survival. Combined compression effectiveness and cardiac activity measures have added prognostic significance: organised cardiac activity seen on ultrasound following pulseless electrical activity (PEA) arrest or asystole is associated with increased survival compared to disorganised activity,²⁸  intra-arrest knowledge that can help inform the resuscitation timeline.

Penetrating or Significant Blunt Trauma – Rapid hemopericardium evaluation in thoracic trauma cases represents the earliest use of limited cardiac ultrasound by non-cardiologists,²⁹ a practise that sparked debate and has since undergone considerable change. Today, ultrasound in trauma is represented by "extended focused assessment with sonography for trauma" (eFAST), a constellation of images used for detection of intraperitoneal haemorrhage, pericardial tamponade, and haemothorax or pneumothorax.³⁰

Invasive ultrasound may be required in specific image-guided procedures. Transesophageal ultrasound (TUE) provides superior imageing of the posterior heart chambers and valvular structures when compared to TTE, and can be used for better visualisation during compression,³¹  coronary artery bypass graft surgery, transcatheter device placement, or to identify valvular prolapse, rupture, and vegetation in infective endocarditis.³²  Intravascular ultrasound (IVUS) may be performed during cardiac catheterization to directly visualise atherosclerosis within the vessel walls when the extent and severity of stenosis are indeterminant during percutaneous coronary intervention (PCI).³³

Techniques

• The subxiphoid view is the preferred scan to evaluate the entire heart and assess for pericardial fluid as part of  the FAST/eFAST exam. Pericardial effusions are anechoic and typically encircle the heart when clinically significant.
• The parasternal long-axis view enables examination of the morphology and motion of the interventricular septum, left atrium, LV, MV, AV, aortic root, and ascending aorta. LV function can be directly assessed via fractional shortening, or indirectly estimated via E-point septal separation (EPSS). A dilated ascending aorta may indicate type A aortic dissection in the appropriate clinical context. 
• The parasternal short-axis view at the level of the LV is a circular look at the walls of the LV and is ideal for evaluation of wall motion and overall contractility of the heart muscle.
• The apical 4 chamber view is ideal for comparison of the left and right sides of the heart.  In this view it is possible to identify pericardial effusion and cardiac tamponade.

Ultrasound-guided pericardiocentesis is typically performed using subxiphoid view, but apical 4-chamber views may also be used, depending on patient habitus, positioning, and which axis of the heart is optimally viewed.

Fujifilm Sonosite: Innovators in the Cardiac Ultrasound Space

At FUJIFILM Sonosite, we understand the need to balance the demands of increasing cardiovascular disease with the constant pressure to improve department efficiency. Our POCUS systems are designed to deliver instant and reproducible results at the patient’s bedside with profound diagnostic, prognostic, and treatment implications, helping triage, determine clinical pathways, and guide procedures and resuscitation. They are routinely used in TTE goal-directed echocardiography, IVC collapsibility/stroke volume assessments to determine fluid responsiveness, RUSH exam for shock and hypotension, and TEE echocardiography for shock and cardiac arrest, and feature:

• Improved 2D and colour doppler imageing for enhanced speed and confidence in clinical interpretation;
• Intuitive user interface that reduces administration tasks, coordinates workflows, and automates data across the POCUS service line;
• Quick boot-up (under 25 seconds) from cold start to live scanning;
• Improved ergonomics and fluid-resistant surfaces for simplified cleaning and disinfection.
   

Learn how FUJIFILM Sonosite products can enhance your practise:

• Sonosite LX: Advanced image clarity on an expansive touchscreen display that allows rotation and extension for easy viewing with clinical team members and consultation with patients.
• Sonosite PX: combines Sonosite’s most advanced image clarity with improved colour sensitivity for accurate blood flow or inflammation assessment, and adaptable horizontal-to-vertical work surface for optimal bedside ergonomics.
• Sonosite SII: designed to maximize productivity, this Continuous Wave and Pulsed Wave Doppler imageing system can be used across multiple hospital environments, including a zero-footprint option for space-constrained rooms. 
• Sonosite Edge II: Truly portable (can be used on or off the optional Edge Stand) with a simplified interface for intuitive access to frequently used functions.
• Sonosite M Turbo: Engineered for portability and unmatched durability, can be used for a wide range of diagnostic and procedural applications.