Multimodality Cardiac Imaging in Ischemic Stroke: Insights into the Heart-Brain Interaction

Approximately 7.6 million individuals experience a new ischemic stroke each year, and roughly 25% of all ischemic strokes are cardiogenic in origin, carrying a high risk of recurrence, death, and disability. To prevent future ischemic strokes, especially in younger individuals, it is crucial to detect and treat direct and indirect cardioembolic sources.

Cardiac imaging is a rapidly evolving field, and post-stroke cardiac imaging is no longer limited to echocardiography but also includes other imaging techniques, such as cardiac magnetic resonance imaging and cardiac computed tomography. Clinicians must be familiar with numerous cardiac and systemic disorders related to stroke and consider the possibilities that imaging diagnostics have to offer. Additional diagnostic tests, such as pre- and transcranial ultrasound with a bubble test, can also increase the diagnostic accuracy for detecting right-left shunt embolisms. Moreover, a patent foramen ovale (PFO) has traditionally been considered as a minor or uncertain risk factor for ischemic stroke. However, PFO-associated strokes are a distinct category among the cardioembolic sources, as in most cases, we do not assume that the thrombus has been developed in situ in the PFO structure or elsewhere intracardially, rather, the PFO merely acts as a mediator for a paradoxical, venous embolism. The article has two parts: Part I, the heart-brain axis, describes multimodality cardiac imaging in the assessment of cardioembolic sources of ischemic stroke, with a special focus on disorders that traditionally have received little attention in the literature. Part II discusses the brain-heart axis, namely, when acute cerebrovascular events lead to cardiac dysfunction, for example, neurogenic stunned myocardium and Takotsubo syndrome.

Advances in cardiovascular imaging have significantly enhanced the detection of cardiac disorders associated with stroke. Clinicians involved in post-stroke workup need to be aware of the capabilities of different imaging modalities to ensure high diagnostic accuracy in order to effectively treat and prevent stroke recurrence.