Prevalence and prognostic significance of low QRS voltage among the three main types of cardiac amyloidosis

Epidemiology, diagnosis, and management of cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative restrictive cardiomyopathy caused by the deposition of amyloid fibrils in the myocardium. It manifests in two primary subtypes: transthyretin cardiac amyloidosis (ATTR) and immunoglobulin light chain cardiac amyloidosis (AL). ATTR is further classified into wild-type and hereditary based on transthyretin gene mutation. Advances in diagnostics and therapeutics have transformed CA from a rare and untreatable condition to a more prevalent and manageable disease. Noninvasive diagnostic tools such as electrocardiography, echocardiography, and cardiac magnetic resonance can raise suspicion for CA; bone scintigraphy can non-invasively confirm ATTR, while AL necessitates histological confirmation. The severity of ATTR and AL can be assessed through serum biomarker-based staging. Treatment approaches differ, ranging from silencing or stabilizing transthyretin and degrading amyloid fibrils in ATTR to employing anti-plasma cell therapies and autologous stem cell transplantation in AL.

Electrocardiographic Patterns and Arrhythmias in Cardiac Amyloidosis: From Diagnosis to Therapeutic Management-A Narrative Review

Electrophysiological aspects of cardiac amyloidosis (CA) are still poorly explored compared to other aspects of the disease. However, electrocardiogram (ECG) abnormalities play an important role in CA diagnosis and prognosis and the management of arrhythmias is a crucial part of CA treatment. Low voltages and a pseudonecrosis pattern with poor R-wave progression in precordial leads are especially common findings. These are useful for CA diagnosis and risk stratification, especially when combined with clinical or echocardiographic findings. Both ventricular and supraventricular arrhythmias are common in CA, especially in transthyretin amyloidosis (ATTR), and their prevalence is related to disease progression. Sustained and non-sustained ventricular tachycardias' prognostic role is still debated, and, to date, there is a lack of specific indications for implantable cardiac defibrillator (ICD). On the other hand, atrial fibrillation (AF) is the most common supraventricular arrhythmia with a prevalence of up to 88% of ATTR patients. Anticoagulation should be considered irrespective of CHADsVA score. Furthermore, even if AF seems to not be an independent prognostic factor in CA, its treatment for symptom control is still crucial. Finally, conduction disturbances and bradyarrhythmias are also common, requiring pacemaker implantation in up to 40% of patients.

Recent advances in the diagnostic methods and therapeutic strategies of transthyretin cardiac amyloidosis

Cardiac amyloidosis is a progressive disease characterized by the buildup of amyloid fibrils in the extracellular space of the heart. It is divided in 2 main types, immunoglobulin light chain amyloidosis and transthyretin amyloidosis (ATTR), and ATTR amyloidosis is further divided in 2 subtypes, non-hereditary wild type ATTR and hereditary mutant variant amyloidosis. Incidence and prevalence of ATTR cardiac amyloidosis is increasing over the last years due to the improvements in diagnostic methods. Survival rates are improving due to the development of novel therapeutic strategies. Tafamidis is the only disease-modifying approved therapy in ATTR amyloidosis so far. However, the most recent advances in medical therapies have added more options with the potential to become part of the therapeutic armamentarium of the disease. Agents including acoramidis, eplontersen, vutrisiran, patisiran and anti-monoclonal antibody NI006 are being investigated on cardiac function in large, multicenter controlled trials which are expected to be completed within the next 2-3 years, providing promising results in patients with ATTR cardiac amyloidosis. However, further and ongoing research is required in order to improve diagnostic methods that could provide an early diagnosis, as well as survival and quality of life of these patients.

Prevalence and clinical significance of low QRS voltages in healthy individuals, athletes, and patients with cardiomyopathy: implications for sports pre-participation cardiovascular screening

Low QRS voltages (LQRSV), defined as a QRS amplitude from peak to nadir < 0.5 mV in all limb leads, are an emerging diagnostic finding on the electrocardiogram (ECG). In healthy individuals and athletes, LQRSV are rare (2.2-4% of elite athletes, 0.5% of recreational athletes, and 0.3% of sedentary individuals). LQRSV athletes commonly show ventricular arrhythmias (VAs) on exercise, and up to 40% of those with LQRSV and VAs have late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). The prevalence of LQRSV in arrhythmogenic cardiomyopathy ranges from 17-40%, predicts left ventricular (LV) involvement, and is correlated with more extensive LGE replacement on CMR. In hypertrophic cardiomyopathy (HCM), LQRSV ranges from 0.7-11%. LQRSV-HCM patients have more segments with LGE, despite relatively smaller LV mass, suggesting a more advanced clinical stage and a worse prognosis. In dilated cardiomyopathy (DCM), LQRSV range from 6-7%, but may be higher (36%) in certain genetic forms of DCM. On a follow-up, LQRSV are independently associated with incident cardiac events, such as sudden death, sustained ventricular arrhythmia, or appropriate internal cardioverter defibrillator discharge. In cardiac amyloid, LQRSV range from 34-66% and demonstrate a negative prognostic value, with worse clinical outcomes regardless of underlying biologic, genetic, and clinical variables. In conclusion, LQRSV deserve careful consideration for exclusion of arrhythmogenic substrates in healthy individuals, athletes, and patients. While additional research is needed, it is reasonable that LQRSV should trigger clinical investigation to exclude underlying diseases at risk of life-threatening arrhythmias.

Electrocardiographic features and rhythm disorders in cardiac amyloidosis

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy caused by extracellular deposition of amyloid fibrils, mainly derived from transthyretin, either wild-type or hereditary variants, or immunoglobulin light chains misfolding. It is characterized by an increased left ventricular (LV) mass and diastolic dysfunction, which can lead to heart failure with preserved ejection fraction and/or conduction disturbances. The diagnosis is based on invasive pathology demonstration of amyloid deposits, or non-invasive criteria using advanced cardiovascular imaging techniques. Nevertheless, 12-lead electrocardiogram (ECG) remains of crucial importance in the assessment of patients with CA, since they can manifest peculiar features such as low QRS voltages, in discordance with the LV hypertrophy, but also pseudo-infarction patterns, sinus node dysfunction, atrioventricular blocks, premature supraventricular and ventricular beats, which support the presence of a myocardial disease. Great awareness of these common ECG characteristics of CA is needed to increase diagnostic performance and improve patient's outcome. In the present review, we discuss the current role of the ECG in the diagnosis and management of CA, focusing on the most common ECG abnormalities and rhythm disorders.

How Artificial Intelligence Can Enhance the Diagnosis of Cardiac Amyloidosis: A Review of Recent Advances and Challenges

Cardiac amyloidosis (CA) is an underdiagnosed form of infiltrative cardiomyopathy caused by abnormal amyloid fibrils deposited extracellularly in the myocardium and cardiac structures. There can be high variability in its clinical manifestations, and diagnosing CA requires expertise and often thorough evaluation; as such, the diagnosis of CA can be challenging and is often delayed. The application of artificial intelligence (AI) to different diagnostic modalities is rapidly expanding and transforming cardiovascular medicine. Advanced AI methods such as deep-learning convolutional neural networks (CNNs) may enhance the diagnostic process for CA by identifying patients at higher risk and potentially expediting the diagnosis of CA. In this review, we summarize the current state of AI applications to different diagnostic modalities used for the evaluation of CA, including their diagnostic and prognostic potential, and current challenges and limitations.

2024 Australia-New Zealand Expert Consensus Statement on Cardiac Amyloidosis

Over the past 5 years, early diagnosis of and new treatments for cardiac amyloidosis (CA) have emerged that hold promise for early intervention. These include non-invasive diagnostic tests and disease modifying therapies. Recently, CA has been one of the first types of cardiomyopathy to be treated with gene editing techniques. Although these therapies are not yet widely available to patients in Australia and New Zealand, this may change in the near future. Given the rapid pace with which this field is evolving, it is important to view these advances within the Australian and New Zealand context. This Consensus Statement aims to update the Australian and New Zealand general physician and cardiologist with regards to the diagnosis, investigations, and management of CA.

Chest pain in a patient with transthyretin cardiac amyloidosis: A case report

Key Clinical Message

Patients with transthyretin cardiac amyloidosis (ATTR-CM) commonly present with dyspnea, fatigue, and edema. In our case, the main presentation was exertional angina, which was atypical in patients with ATTR-CM and should be paid more attention to.

Abstract

A 54-year-old woman was admitted with a complaint of exertional chest pain, and she had a history of hypertension. The results of the electrocardiogram and echocardiography revealed the clues of cardiac amyloidosis, and the patient was finally diagnosed with transthyretin cardiac amyloidosis, then she received tafamidis, and the symptoms improved significantly.

Prognostic value of native T1 and extracellular volume in patients with immunoglubin light-chain amyloidosis

BACKGROUND

Cardiac involvement in patients with immunoglubin light-chain amyloidosis (AL) is a major determinant of treatment choice and prognosis, and early identification of high-risk patients can initiate intensive treatment strategies to achieve better survival. This study aimed to investigate the prognostic value of native T1 and ECV in patients with AL-cardiac amyloidosis (CA).

METHODS

A total of 38 patients (mean age 59 ± 11 years) with AL diagnosed histopathologically from July 2017 to October 2021 were collected consecutively. All patients were performed 3.0-T cardiac magnetic resonance (CMR) including cine, T1 mapping, and late gadolinium enhancement (LGE). Pre- and post-contrast T1 mapping images were transferred to a dedicated research software package (CVI42 v5.11.3) to create parametric T1 and ECV values. In addition, clinical and laboratory data of all patients were collected, and patients or their family members were regularly followed up by telephone every 3 months. The starting point of follow-up was the time of definitive pathological diagnosis, and the main endpoint was all-cause death. Kaplan-Meier analysis and Cox proportional risk model were used to evaluate the association between native T1 and ECV and death in patients with CA.

RESULTS

After a median follow-up of 27 (16, 37) months, 12 patients with CA died. Kaplan-Meier analysis showed that elevated native T1 and ECV were closely associated with poor prognosis in patients with CA. The survival rate of patients with ECV > 44% and native T1 > 1389ms were significantly lower than that of patients with ECV ≤ 44% and native T1 ≤ 1389ms (Log-rank P < 0.001), and was not associated with the presence of LGE. After adjusting for clinical risk factors and CMR measurements in a stepwise multivariate Cox regression model, ECV [risk ratio (HR):1.37, 95%CI: 1.09-1.73, P = 0.008] and native T1 (HR:1.01, 95%CI: 1.00-1.02, P = 0.037) remained independent predictors of all-cause mortality in patients with CA.

CONCLUSIONS

Both native T1 and ECV were independently prognostic for mortality in patients with CA, and can be used as important indicators for clinical prognosis assessment of AL.

Perioperative implications of amyloidosis and amyloid cardiomyopathy: A review for anesthesiologists

It is well recognized that amyloid protein can infiltrate many regions of the body. This can include the peripheral nerves, the liver, kidney, spleen, the gastrointestinal tract, and most importantly the myocardium. The amyloid proteins that cause cardiomyopathy may come from genetically altered liver genes (transthyretin amyloid, ATTR) or from the bone marrow with malignant plasma cells (light chain amyloid, AL) generating the aberrant protein. These two types of amyloidosis cause significant damaging effects on both the myocardial cells as well as the conduction system of the heart. The resultant changes can produce dyspnea and exercise intolerance which is thought to be secondary to diastolic dysfunction and reduced stroke volume. This subclinical decompensation poses a significant problem for members of a care team as it often goes unrecognized. In the operating room patients are exposed to dramatic hemodynamic changes and may have difficult airways, autonomic dysfunction, and conduction abnormalities. Although the topic of amyloidosis is well described in cardiology literature, it is underdiagnosed. The purpose of this review is to describe some of the pathophysiology behind the principle proteins that cause cardiac amyloidosis and to comprehensively describe perioperative considerations for anesthesia providers.

Advances in the diagnosis and treatment of transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underrecognized cause of heart failure (HF). ATTR-CM can lead to a number of cardiovascular manifestations including HF, rhythm disturbances, and valvular disease that ultimately limit quality of life and prognosis. Due to advances in diagnostic modalities and therapeutic options, the prevalence of ATTR-CM is rising. There are several classes of medications under active investigation, though most therapies are most efficacious if instituted early on in the disease course. As such, early clinical recognition and prompt diagnosis are crucial to improving disease related outcomes. In this review, we highlight clinical manifestations of ATTR-CM as well as contemporary diagnostic and treatment approaches to the disease.

Electrocardiographic abnormalities in patients with cardiomyopathies

Abnormalities in impulse generation and transmission are among the first signs of cardiac remodeling in cardiomyopathies. Accordingly, 12-lead electrocardiogram (ECG) of patients with cardiomyopathies may show multiple abnormalities. Some findings are suggestive of specific disorders, such as the discrepancy between QRS voltages and left ventricular (LV) mass for cardiac amyloidosis or the inverted T waves in the right precordial leads for arrhythmogenic cardiomyopathy. Other findings are less sensitive and/or specific, but may orient toward a specific diagnosis in a patient with a specific phenotype, such as an increased LV wall thickness or a dilated LV. A "cardiomyopathy-oriented" mindset to ECG reading is important to detect the possible signs of an underlying cardiomyopathy and to interpret correctly the meaning of these alterations, which differs in patients with cardiomyopathies or other conditions.

Diagnostic significance of paradoxical left ventricular hypertrophy in detecting cardiac amyloidosis

Background

Cardiac amyloidosis (CA) progresses rapidly with a poor prognosis. Therefore, methods for early diagnosis that are easily accessible in any hospital, are required. We hypothesized that based on the pathology of CA, morphological left ventricular hypertrophy (LVH) without electrical augmentation, namely paradoxical LVH, could be used to diagnose CA. This study aimed to investigate whether paradoxical LVH has diagnostic significance in identifying CA in patients with LVH.

Methods

Patients who presented with left ventricular (LV) wall thickness ≥ 12 mm on cardiac magnetic resonance (CMR) were enrolled from a multicentre CMR registry. Paradoxical LVH was defined as a LV wall thickness ≥ 12 mm on CMR, SV1 + RV5 < 3.5 mV, and a lack of secondary ST-T abnormalities. The diagnostic significance of paradoxical LVH in identifying CA was assessed.

Results

Of the 110 patients enrolled, 30 (27 %) were diagnosed with CA and 80 (73 %) with a non-CA aetiology. The CA group demonstrated paradoxical LVH more frequently than the non-CA group (80 % vs. 16 %, P < 0.001). It was an independent predictor for detecting CA in patients with LVH (odds ratio: 33.44, 95 % confidence interval: 8.325-134.3, P < 0.001). The sensitivity, specificity, positive predict value, negative predict value and accuracy of paradoxical LVH for CA detection were 80 %, 84 %, 65 %, 92 % and 83 %, respectively.

Conclusions

Paradoxical LVH can be used for identifying CA in patients with LVH. Our findings could contribute to the early diagnosis of CA, even in non-specialized hospitals.

Cardiac amyloidosis and aortic stenosis: a state-of-the-art review

Cardiac amyloidosis is caused by the extracellular deposition of amyloid fibrils in the heart, involving not only the myocardium but also any cardiovascular structure. Indeed, this progressive infiltrative disease also involves the cardiac valves and, specifically, shows a high prevalence with aortic stenosis. Misfolded protein infiltration in the aortic valve leads to tissue damage resulting in the onset or worsening of valve stenosis. Transthyretin cardiac amyloidosis and aortic stenosis coexist in patients > 65 years in about 4-16% of cases, especially in those undergoing transcatheter aortic valve replacement. Diagnostic workup for cardiac amyloidosis in patients with aortic stenosis is based on a multi-parametric approach considering clinical assessment, electrocardiogram, haematologic tests, basic and advanced echocardiography, cardiac magnetic resonance, and technetium labelled cardiac scintigraphy like technetium-99 m (99mTc)-pyrophosphate, 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid, and 99mTc-hydroxymethylene diphosphonate. However, a biopsy is the traditional gold standard for diagnosis. The prognosis of patients with coexisting cardiac amyloidosis and aortic stenosis is still under evaluation. The combination of these two pathologies worsens the prognosis. Regarding treatment, mortality is reduced in patients with cardiac amyloidosis and severe aortic stenosis after undergoing transcatheter aortic valve replacement. Further studies are needed to confirm these findings and to understand whether the diagnosis of cardiac amyloidosis could affect therapeutic strategies. The aim of this review is to critically expose the current state-of-art regarding the association of cardiac amyloidosis with aortic stenosis, from pathophysiology to treatment.

World Heart Federation Consensus on Transthyretin Amyloidosis Cardiomyopathy (ATTR-CM)

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and fatal condition that requires early diagnosis, management, and specific treatment. The availability of new disease-modifying therapies has made successful treatment a reality. Transthyretin amyloid cardiomyopathy can be either age-related (wild-type form) or caused by mutations in the TTR gene (genetic, hereditary forms). It is a systemic disease, and while the genetic forms may exhibit a variety of symptoms, a predominant cardiac phenotype is often present. This document aims to provide an overview of ATTR-CM amyloidosis focusing on cardiac involvement, which is the most critical factor for prognosis. It will discuss the available tools for early diagnosis and patient management, given that specific treatments are more effective in the early stages of the disease, and will highlight the importance of a multidisciplinary approach and of specialized amyloidosis centres. To accomplish these goals, the World Heart Federation assembled a panel of 18 expert clinicians specialized in TTR amyloidosis from 13 countries, along with a representative from the Amyloidosis Alliance, a patient advocacy group. This document is based on a review of published literature, expert opinions, registries data, patients' perspectives, treatment options, and ongoing developments, as well as the progress made possible via the existence of centres of excellence. From the patients' perspective, increasing disease awareness is crucial to achieving an early and accurate diagnosis. Patients also seek to receive care at specialized amyloidosis centres and be fully informed about their treatment and prognosis.

Prognostic Value of Electrocardiographic Left Ventricular Hypertrophy After Transcatheter Aortic Valve Implantation: Insights from the OCEAN-TAVI Registry

Electrocardiogram (ECG) left ventricular hypertrophy (LVH) is associated with the prognosis of patients with aortic stenosis. However, the impact of the presence or absence of ECG-LVH on the clinical outcomes after transcatheter aortic valve implantation (TAVI) is limited. This study aimed to assess the prognostic value of ECG-LVH among patients with aortic stenosis treated by TAVI. A total of 1,667 patients who underwent TAVI were prospectively enrolled into the OCEAN-TAVI (Optimized CathEter vAlvular iNtervention-Transcatheter Aortic Valve Implantation) registry. A total of 1,446 patients (mean age 84 years; 29.9% men) were analyzed. The Sokolow-Lyon index was used to determine the presence of ECG-LVH. LVH was also assessed using transthoracic echocardiography (TTE). We investigated the association between ECG-LVH and all-cause and cardiovascular mortality. This study identified ECG-LVH and TTE-LVH in 743 (51.5%) and 1,242 patients (86.0%), respectively. The Kaplan-Meier analysis revealed that all-cause mortality was significantly higher among patients without ECG-LVH than among those with ECG-LVH (log-rank p <0.001). In the multivariable analysis, the absence of ECG-LVH was independently associated with all-cause mortality (hazard ratio 1.98, 95% confidence interval 1.39 to 2.82, p <0.001), regardless of the presence or absence of TTE-LVH. Furthermore, the presence of TTE-LVH with the absence of ECG-LVH was observed in 575 patients (40%), which was associated with cardiovascular mortality (hazard ratio 2.84, 95% confidence interval 1.56 to 5.17, p <0.001). In conclusion, the absence of ECG-LVH was independently associated with an increased risk of all-cause mortality after TAVI. Risk stratification using both ECG-LVH and TTE-LVH is a useful predictor of adverse clinical outcomes after TAVI.

Low QRS voltages and left ventricular hypertrophy: a risky association

AIMS

Low QRS voltages (LQRSV) are an unexpected finding in left ventricular hypertrophy, i.e. hypertrophic cardiomyopathy (HCM) or athlete's heart.

METHODS AND RESULTS

Prevalence and clinical correlates of LQRSV were investigated in 197 consecutive HCM patients, aged 58 ± 13 years and comparatively in 771 Olympic athletes, aged 23 ± 4. Clinical characterization included family/personal history, symptoms, New York Heart Association (NYHA) functional class, electrocardiographic pattern, ventricular arrhythmias, and cardiac magnetic resonance (CMR). Twenty-two (11%) of HCM and 18 (2.3%) of athletes presented LQRSV. At initial evaluation, in HCM, LQRSV showed no differences vs. non-LQRSV for functional class (90% vs. 91%, in Classes I and II; P = 0.983), symptoms (27% vs. 18%; P = 0.478), and ventricular arrhythmias (40% vs. 39%; P = 857) but showed larger extent of late gadolinium enhancement (LGE) at CMR (4.1 ± 1.5 vs. 1.5 ± 0.7 affected segments; P < 0.001). In athletes, LQRSV was associated with larger prevalence of inverted T-waves (22% vs. 9%; P < 0.001) and ventricular arrhythmias (28% vs. 8%; P = 0.005). In one LQRSV athlete, arrhythmogenic cardiomyopathy was identified. Over 4.5 ± 2.6-year follow-up, presence of LQRSV in HCM was associated with larger incidence of functional deterioration (31% vs. 14%; P = 0.038), stroke (22% vs. 6%; P = 0.008), and implantable cardioverter defibrillator (ICD) implant (27% vs. 10%; P = 0.015). No clinical events occurred in LQRSV athletes without initial evidence of cardiac disease.

CONCLUSION

LQRSV are relatively common (11%) in HCM and have clinical relevance, being predictive over a medium term for a worsening functional class, incidence of stroke, and ICD implant. Instead, LQRSV are rare (2.3%) in athletes but may occasionally be a marker that raises suspicion for underlying cardiac disease at risk.

Cardiac Amyloidosis Imaging, Part 3: Interpretation, Diagnosis, and Treatment

Cardiac amyloidosis was thought to be rare, undiagnosable, and incurable. However, recently it has been discovered to be common, diagnosable, and treatable. This knowledge has led to a resurgence in nuclear imaging with ^99mTc-pyrophosphate-a scan once believed to be extinct-to identify cardiac amyloidosis, particularly in patients with heart failure but preserved ejection fraction. The renewed interest in ^99mTc-pyrophosphate imaging has compelled technologists and physicians to reacquaint themselves with the procedure. Although ^99mTc-pyrophosphate imaging is relatively simple, interpretation and diagnostic accuracy require an in-depth knowledge of amyloidosis etiology, clinical manifestations, disease progression, and treatment. Diagnosing cardiac amyloidosis is complicated because typical signs and symptoms are nonspecific and usually attributed to other cardiac disorders. In addition, physicians must be able to differentiate between monoclonal immunoglobulin light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Several clinical and noninvasive diagnostic imaging (echocardiography and cardiac MRI) red flags have been identified that suggest a patient may have cardiac amyloidosis. The intent of these red flags is to raise physician suspicion of cardiac amyloidosis and guide a series of steps (a diagnostic algorithm) for narrowing down and diagnosing the specific amyloid type. One element in the diagnostic algorithm is to identify monoclonal proteins indicative of AL. Monoclonal proteins are detected by serum or urine immunofixation electrophoresis and serum free light-chain assay. Another element is identifying and grading cardiac amyloid deposition using ^99mTc-pyrophosphate imaging. When monoclonal proteins are present and the ^99mTc-pyrophosphate scan is positive, the patient should be further evaluated for cardiac AL. The absence of monoclonal proteins and a positive ^99mTc-pyrophosphate scan is diagnostic for cardiac ATTR. Patients with cardiac ATTR need to undergo genetic testing to differentiate between wild-type ATTR and variant ATTR. This article is the third in a 3-part series in this issue of the Journal of Nuclear Medicine Technology Part 1 reviewed amyloidosis etiology and outlined ^99mTc-pyrophosphate study acquisition. Part 2 described ^99mTc-pyrophosphate image quantification and protocol technical considerations. This article discusses scan interpretation along with cardiac amyloidosis diagnosis and treatment.

Beta 2-microglobulin: case report of a rare cause of cardiac amyloidosis

Background

Cardiac amyloidosis is caused by the deposition of misfolded proteins in the myocardium. The majority of cases of cardiac amyloidosis is caused by misfolded transthyretin or light chain proteins. In this case report, we discuss a case of a rare form of cardiac amyloidosis related to beta 2-microglobulin (B2M) in a patient not on dialysis.

Case summary

A 63-year-old man was referred for workup of possible cardiac amyloidosis. Serum and urine immunofixation electrophoresis demonstrated no monoclonal bands, and the serum kappa/lambda light chain ratio was normal, excluding light chain amyloidosis. Bone scintigraphy imaging showed diffuse radiotracer uptake in the myocardium, and genetic testing of the Transthyretin gene was negative for variants. This workup was consistent with wild-type transthyretin cardiac amyloidosis. The patient, however, later underwent endomyocardial biopsy due to factors inconsistent with this diagnosis, including a young age of presentation and a strong family history of cardiac amyloidosis despite no variants in the Transthyretin gene. This showed B2M-type amyloidosis, and genetic testing of the B2M gene showed a heterozygous Pro32Leu (p. P52L) mutation. The patient underwent heart transplantation with normal graft function 2 years post transplant.

Discussion

While contemporary advancements allow for the non-invasive diagnosis of transthyretin cardiac amyloidosis with positive bone scintigraphy and negative monoclonal protein screen, clinicians should be aware of rarer forms of amyloidosis where endomyocardial biopsy is required to make the diagnosis.

State of the Art of Cardiac Amyloidosis

Cardiac amyloidosis is defined by extracellular deposition of misfolded proteins in the heart. The most frequent cases of cardiac amyloidosis are caused by transthyretin and light chain amyloidosis. This condition is underdiagnosed, and its incidence has been continuously rising in recent studies because of the aging of the population and the development of noninvasive multimodal diagnostic tools. Amyloid infiltration affects all cardiac tunics and causes heart failure with preserved ejection fraction, aortic stenosis, arrythmia, and conductive disorder. Innovative, specific therapeutic approaches have demonstrated an improvement in affected organs and the global survival of patients. This condition is no longer considered rare and incurable. Thus, better knowledge of the disease is mandatory. This review will provide a digest of the clinical signs and symptoms of cardiac amyloidosis, the diagnostic tools used to confirm the diagnosis, and current symptomatic and etiopathogenic management considerations according to guidelines and recommendations.

Risk stratification in transthyretin-related cardiac amyloidosis

Transthyretin related cardiac amyloidosis (TTR-CA) is an infiltrative cardiomyopathy that cause heart failure with preserved ejection fraction, mainly in aging people. Due to the introduction of a non invasive diagnostic algorithm, this disease, previously considered to be rare, is increasingly recognized. The natural history of TTR-CA includes two different stages: a presymptomatic and a symptomatic stage. Due to the availability of new disease-modifying therapies, the need to reach a diagnosis in the first stage has become impelling. While in variant TTR-CA an early identification of the disease may be obtained with a genetic screening in proband's relatives, in the wild-type form it represents a challenging issue. Once the diagnosis has been made, in order to identifying patients with a higher risk of cardiovascular events and death it is necessary to focus on risk stratification. Two prognostic scores have been proposed both based on biomarkers and laboratory findings. However, a multiparametric approach combining information from electrocardiogram, echocardiogram, cardiopulmonary exercise test and cardiac magnetic resonance may be warranted for a more comprehensive risk prediction. In this review, we aim at evaluating a step by step risk stratification, providing a clinical diagnostic and prognostic approach for the management of patients with TTR-CA.

Machine Learning Approaches in Diagnosis, Prognosis and Treatment Selection of Cardiac Amyloidosis

Cardiac amyloidosis is an uncommon restrictive cardiomyopathy featuring an unregulated amyloid protein deposition that impairs organic function. Early cardiac amyloidosis diagnosis is generally delayed by indistinguishable clinical findings of more frequent hypertrophic diseases. Furthermore, amyloidosis is divided into various groups, according to a generally accepted taxonomy, based on the proteins that make up the amyloid deposits; a careful differentiation between the various forms of amyloidosis is necessary to undertake an adequate therapeutic treatment. Thus, cardiac amyloidosis is thought to be underdiagnosed, which delays necessary therapeutic procedures, diminishing quality of life and impairing clinical prognosis. The diagnostic work-up for cardiac amyloidosis begins with the identification of clinical features, electrocardiographic and imaging findings suggestive or compatible with cardiac amyloidosis, and often requires the histological demonstration of amyloid deposition. One approach to overcome the difficulty of an early diagnosis is the use of automated diagnostic algorithms. Machine learning enables the automatic extraction of salient information from “raw data” without the need for pre-processing methods based on the a priori knowledge of the human operator. This review attempts to assess the various diagnostic approaches and artificial intelligence computational techniques in the detection of cardiac amyloidosis.

A Review of Current and Evolving Imaging Techniques in Cardiac Amyloidosis

Purpose of review

Establishing an early, efficient diagnosis for cardiac amyloid (CA) is critical to avoiding adverse outcomes. We review current imaging tools that can aid early diagnosis, offer prognostic information, and possibly track treatment response in CA.

Recent findings

There are several current conventional imaging modalities that aid in the diagnosis of CA including electrocardiography, echocardiography, bone scintigraphy, cardiac computed tomography (CT), and cardiac magnetic resonance (CMR) imaging. Advanced imaging techniques including left atrial and right ventricular strain, and CMR T1 and T2 mapping as well as ECV quantification may provide alternative non-invasive means for diagnosis, more granular prognostication, and the ability to track treatment response.

Summary

Leveraging a multimodal imaging toolbox is integral to the early diagnosis of CA; however, it is important to understand the unique role and limitations posed by each modality. Ongoing studies are needed to help identify imaging markers that will lead to an enhanced ability to diagnose, subtype and manage this condition.

Artificial Intelligence Enabled Classification of Hypertrophic Heart Diseases Using Electrocardiograms

Background

Differentiating among cardiac diseases associated with left ventricular hypertrophy (LVH) informs diagnosis and clinical care.

Objective

To evaluate if artificial intelligence-enabled analysis of the 12-lead electrocardiogram (ECG) facilitates automated detection and classification of LVH.

Methods

We used a pretrained convolutional neural network to derive numerical representations of 12-lead ECG waveforms from patients in a multi-institutional healthcare system who had cardiac diseases associated with LVH (n = 50,709), including cardiac amyloidosis (n = 304), hypertrophic cardiomyopathy (n = 1056), hypertension (n = 20,802), aortic stenosis (n = 446), and other causes (n = 4766). We then regressed LVH etiologies relative to no LVH on age, sex, and the numerical 12-lead representations using logistic regression ("LVH-Net"). To assess deep learning model performance on single-lead data analogous to mobile ECGs, we also developed 2 single-lead deep learning models by training models on lead I ("LVH-Net Lead I") or lead II ("LVH-Net Lead II") from the 12-lead ECG. We compared the performance of the LVH-Net models to alternative models fit on (1) age, sex, and standard ECG measures, and (2) clinical ECG-based rules for diagnosing LVH.

Results

The areas under the receiver operator characteristic curve of LVH-Net by specific LVH etiology were cardiac amyloidosis 0.95 [95% CI, 0.93-0.97], hypertrophic cardiomyopathy 0.92 [95% CI, 0.90-0.94], aortic stenosis LVH 0.90 [95% CI, 0.88-0.92], hypertensive LVH 0.76 [95% CI, 0.76-0.77], and other LVH 0.69 [95% CI 0.68-0.71]. The single-lead models also discriminated LVH etiologies well.

Conclusion

An artificial intelligence-enabled ECG model is favorable for detection and classification of LVH and outperforms clinical ECG-based rules.

Cardiac Amyloidosis

Amyloidosis is a pathologic and clinical condition resulting from the accumulation of insoluble aggregates of misfolded proteins in tissues. Extracellular deposition of amyloid fibrils in the myocardium leads to cardiac amyloidosis, which is often overlooked as a cause of diastolic heart failure. Although cardiac amyloidosis was previously believed to have a poor prognosis, recent advances in diagnosis and treatment have emphasized the importance of early recognition and changed management of this condition. This article provides an overview of cardiac amyloidosis and summarizes current screening, diagnosis, evaluation, and treatment options.

[Functional methods of amyloid cardiomyopathy diagnostic in practice and in expert centers: A review]

The article is a set of recommendations for the interpretation of electrocardiography and echocardiography data in patients with suspected amyloidosis of the heart. Amyloid cardiomyopathy is a progressive disease characterized by a detailed picture of congestive heart failure, poor quality of life and poor prognosis. Currently, medications have appeared that can improve the prognosis in patients with amyloidosis of the heart. Therefore, raising awareness of specialists about specific instrumental signs of the disease is an important and urgent task.

[Current role of imaging techniques in cardiac amyloidosis]

Cardiac amyloidosis (CA) is an underdiagnosed disease and, if left untreated, rapidly fatal. Emerging therapies for CA increase the urgency of developing non-invasive diagnostic methods for its early detection and for monitoring therapeutic response. Classic imaging features on echocardiography and cardiac magnetic resonance, although typical for cardiac amyloidosis, are not specific enough to distinguish light chain amyloidosis from transthyretin. Myocardial bone-avid radiotracer uptake is highly specific for transthyretin cardiac amyloidosis when plasma cell dyscrasia has been excluded; it is now replacing the need for biopsy in many patients. Detection of early cardiac amyloidosis, quantitation of its burden, and assessment of response to therapy are important next steps for imaging to advance the evaluation and management of cardiac amyloidosis.

Bad players in AL amyloidosis in the current era of treatment

INTRODUCTION

Systemic AL amyloidosis (ALA) is a clonal plasma cell (PC) disease characterized by deposition of amyloid fibrils in different organs and tissues. Traditionally, the prognosis of ALA is poor and is primarily defined by cardiac involvement. The modern prognostic models are based on cardiac markers and free light chain difference (dFLC). Cardiac biomarkers have low specificity and are dependent on renal function, volume status, and cardiac diseases other than ALA. New therapies significantly improved the prognosis of the disease. The advancements in technologies - cardiac echocardiography (ECHO) and cardiac MRI (CMR), as well as new biological markers, relying on cardiac injury, inflammation, endothelial damage, and clonal and non-clonal PC markers are promising.

AREAS COVERED

An update on the prognostic significance of cardiac ALA, number of involved organs, response to treatment, including minimal residual disease (MRD), ECHO, MRI, and new biological markers will be discussed. The literature search was done in PubMed and Google Scholar, and the most recent and relevant data are included.

EXPERT OPINION

Prospective multicenter trials, evaluating multiple clinical and laboratory parameters, should be done to improve the risk assessment models in ALA in the modern era of therapy.

Primer on the Differential Diagnosis and Workup for Transthyretin Cardiac Amyloidosis

Amyloidosis has often been referred to as a "great masquerader," mimicking other systemic and cardiac diseases. As diagnostic techniques such as echocardiography with longitudinal strain, cardiac magnetic resonance imaging, and nuclear scintigraphy have advanced, identification of cardiac amyloidosis has become less daunting. This review covers the differential diagnosis and workup of patients with transthyretin cardiac amyloidosis, with a specific focus on developing a clinical suspicion through demographic, clinical, and echocardiographic features of the disease. The most common mimics of cardiac amyloidosis, i.e., conditions that likewise cause heart failure with preserved or mildly reduced ejection fraction, are also explored with respect to differential diagnosis, both for patients with normal and increased ventricular wall thickness. Ultimately, this review aims to demystify the diagnostic process by offering an algorithmic approach to the identification of transthyretin cardiac amyloidosis.

Summation of Precordial R Wave Amplitudes, a Clinical Parameter for Detecting Early TTR Amyloidosis Cardiac Involvement

There have been several reports on the identification of the stage of transthyretin amyloid cardiomyopathy (ATTR-CM); however, a staging system for ATTR-CM has not yet been established. An 83-year-old woman was referred to our department about ten years ago. Recently, she was diagnosed with ATTR-CM. The electrocardiogram showed characteristic changes that take place over the duration of ATTR-CM progression. Among these, the precordial R amplitudes abruptly decreased before the development of increased ventricular thickness. This case suggested that the decrease in the precordial R wave amplitudes may represent a new diagnostic clue reflecting early myocardial damage due to ATTR-CM.

[Cardiac progression of systemic light chain amyloidosis]

Systemic light chain amyloidosis is a disease characterized by the accumulation of amyloid protein in multiple organs and systems. We present the case of a 52-year-old male patient with a diagnosis of systemic light chain amyloidosis associated with cardiac and renal involvement. A renal biopsy showed the presence of renal amyloidosis associated with proteinuria, and the patient was referred for cardiovascular evaluation. The baseline electrocardiogram showed micro voltage in frontal leads that were discordant with the left ventricular hypertrophy evidenced in the transthoracic echocardiogram (TTE). Cardiac magnetic resonance imaging (CMR) confirmed the presence of cardiac amyloid infiltration with a pattern of extensive ventricular late-gadolinium enhancement. Despite being referred and receiving specific systemic chemotherapy treatment, the evolution was not favorable after four months of follow-up with worsening cardiac infiltration, increasing values of biomarkers, and progression of dyspnea. The TTE was useful in revealing the unfavorable evolution and worsening of diastolic function parameters and increased wall thickness in the context of infiltration. The electrocardiogram and echocardiogram were easily accessible tools that allowed the monitoring of the response to treatment.

High Hereditary Transthyretin-Related Amyloidosis Prevalence in Crete

Background and Objectives

Our goal was to study hereditary transthyretin-related amyloidosis (hATTR) in Crete, Greece.

Methods

We aimed at ascertaining all hATTR cases in Crete, an island of 0.62 million people. For this, we evaluated patients with polyneuropathy, autonomic involvement, cardiomyopathy, and/or ophthalmopathy suggestive of hATTR, who presented to the physicians of this study or were referred to them by other physicians. Genetic analyses were performed on all patients suspected of suffering from hATTR. We included in our observational longitudinal cohort study all individuals, residents of Crete, who, during the study period (1993–2019), were found to carry a pathogenic TTR variant.

Results

Over the past 27 years, 30 individuals (15 female patients, 15 male patients), from 12 apparently unrelated families, were diagnosed with hATTR, whereas evaluation of their offspring identified 5 asymptomatic TTR pathogenic variant carriers. The most prevalent TTR variant detected was p.Val50Met, affecting 19 patients (11 female patients, 8 male patients) and causing a rather consistent phenotype characterized by predominant polyneuropathy of early adult onset (median age of symptom onset: 30 years; range: 18–37 years). Specifically, patients affected by the p.Val50Met TTR variant experienced progressive sensorimotor disturbances, involving mainly the lower extremities, associated with autonomic and/or gastrointestinal dysfunction. The second most frequent TTR variant was p.Val114Ala, found in 10 patients (4 female patients, 6 male patients) who were affected at an older age (median age of symptom onset: 70 years; range: 54–78 years). This variant caused a predominantly cardiomyopathic phenotype, manifested by congestive heart failure and associated with peripheral neuropathy, carpal tunnel syndrome, and/or autonomic involvement. In these patients, cardiac amyloid deposition was detected on 99m-technetium pyrophosphate scintigraphy and/or heart biopsy. The third TTR variant (p.Arg54Gly) was found in a 50-year-old male patient with ophthalmopathy due to vitreous opacities and positive family history for visual loss. As 22 patients were alive at the end of the study, we calculated the hATTR prevalence in Crete to be 35 cases per 1 million inhabitants.

Discussion

Our study revealed that the prevalence of hATTR in Crete is one of the world's highest. Three different pathogenic TTR variants causing distinct clinical phenotypes were identified in this relatively small population pool.

Cardiac AL amyloidosis presenting as recurrent dyspnoea in a patient with cancer: an important clinical clue to an early diagnosis

Cardiac amyloidosis (CA) is challenging to diagnose due to its non-specific clinical manifestations early in the disease process. We report the case of a patient who presented with dyspnoea, abdominal distension and leg swelling. Medical history was notable for hypertension, recurrent vulvar squamous cell carcinoma and polysubstance abuse. Over 1 year before the official diagnosis of CA, the patient had multiple hospital readmissions for dyspnoea. Our case illustrates the importance of having a high index of clinical suspicion for an early diagnosis of CA. Furthermore, it highlights the need to re-evaluate a presumed diagnosis when a patient's symptoms recur or do not respond to appropriate treatment and to consider the influence of social factors on diagnostic processes.

Red flags for the diagnosis of cardiac amyloidosis: simple suggestions to raise suspicion and achieve earlier diagnosis

Cardiac amyloidosis is an infiltrative disease characterized by extracellular deposition of insoluble amyloid fibrils in the heart leading to organ dysfunction. Despite recent diagnostic advances, the diagnosis of cardiac amyloidosis is often delayed or even missed. Furthermore, a long diagnostic delay is associated with adverse outcomes, with the early diagnosed patients showing the longest survival. In this narrative review we aimed to summarize the 'red flags' that may facilitate the correct diagnosis. The red flags may be classified as clinical, biohumoral, electrocardiographic, echocardiographic, and cardiac magnetic resonance features and should promptly raise the suspicion of cardiac amyloidosis in order to start a correct diagnostic pathway and targeted treatment strategies that may improve patients' outcomes.

[Cardiac amyloidosis: State of art in 2022]

The 3 main types of cardiac amyloidosis are linked to two protein precursors: AL amyloidosis secondary to free light chain deposits in the context of monoclonal gammopathy (mainly of undetermined significance or myeloma) and transthyretin amyloidosis (ATTR), comprising wild-type transthyretin amyloidosis (ATTRwt for wild type) and hereditary transthyretin amyloidosis (ATTRv for variant). These diseases are underdiagnosed and highly prevalent in common cardiac phenotypes in recent studies (heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy). Myocardial amyloid infiltration affects all cardiac structures and clinically promotes predominantly heart failure, conductive disorders and cardioembolic events. The search for extracardiac signs makes it possible to arouse diagnostic suspicion. Electrocardiogram, echocardiography and cardiac MRI can suspect cardiac amyloidosis. The diagnostic confirmation follows a simple algorithm including a systematic search for monoclonal gammapathy and a disphosphonate scintigraphy. Histological proof is necessary in case of AL or ATTR amyloidosis with concomitant monoclonal gammopathy in order to initiate specific treatment. Due to the late disease onset in ATTRv, genetic testing must be routine in all cases of ATTR. These diseases are no longer perceived as incurable since recent therapeutic innovations. A better knowledge of the disease is more than ever necessary.

Prognostic Implications of Right Ventricular Systolic Dysfunction in Cardiac Amyloidosis

Left ventricular (LV) systolic dysfunction in cardiac amyloidosis (CA) is associated with poor prognosis. This study aimed to investigate the prognostic implications of right ventricular (RV) systolic dysfunction in CA. A total of 93 patients diagnosed with CA who underwent standard and speckle-tracking echocardiography were included. During a median follow-up of 17 (5 to 38) months, 42 patients (45%) died. Nonsurvivors were more likely to present with immunoglobulin light-chain amyloidosis and New York Heart Association class III to IV heart failure symptoms. Regarding the echocardiographic characteristics, nonsurvivors had a higher LV apical ratio, worse LV diastolic function, and worse RV systolic function (evaluated with both tricuspid annular plane systolic excursion and RV free wall strain). RV free wall strain was independently associated with all-cause mortality in several multivariable Cox regression models and had incremental prognostic value over conventional parameters of RV function when added to a basal model (including heart failure symptoms, amyloidosis phenotype, and LV global longitudinal strain). Based on spline curve analysis and Youden index, a value of 16% for RV free wall strain was identified as the optimal cutoff to predict outcome and patients with RV free wall strain <16% had a significantly worse short- and long-term survival during follow-up (1- and 3-year cumulative survival: 81% vs 31% and 67% vs 20%, respectively, p <0.001). In conclusion, RV systolic dysfunction is independently associated with poor outcome in patients with CA and the use of advanced echocardiographic parameters, such as RV free wall strain, may be of aid for better risk stratification.

Suspicion, screening, and diagnosis of wild-type transthyretin amyloid cardiomyopathy: a systematic literature review

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt CM) is a more common disease than previously thought. Awareness of ATTRwt CM and its diagnosis has been challenged by its unspecific and widely distributed clinical manifestations and traditionally invasive diagnostic tools. Recent advances in echocardiography and cardiac magnetic resonance (CMR), non-invasive diagnosis by bone scintigraphy, and the development of disease-modifying treatments have resulted in an increased interest, reflected in multiple publications especially during the last decade. To get an overview of the scientific knowledge and gaps related to patient entry, suspicion, diagnosis, and systematic screening of ATTRwt CM, we developed a framework to systematically map the available evidence of (i) when to suspect ATTRwt CM in a patient, (ii) how to diagnose the disease, and (iii) which at-risk populations to screen for ATTRwt CM. Articles published between 2010 and August 2021 containing part of or a full diagnostic pathway for ATTRwt CM were included. From these articles, data for patient entry, suspicion, diagnosis, and screening were extracted, as were key study design and results from the original studies referred to. A total of 50 articles met the inclusion criteria. Of these, five were position statements from academic societies, while one was a clinical guideline. Three articles discussed the importance of primary care providers in terms of patient entry, while the remaining articles had the cardiovascular setting as point of departure. The most frequently mentioned suspicion criteria were ventricular wall thickening (44/50), carpal tunnel syndrome (42/50), and late gadolinium enhancement on CMR (43/50). Diagnostic pathways varied slightly, but most included bone scintigraphy, exclusion of light-chain amyloidosis, and the possibility of doing a biopsy. Systematic screening was mentioned in 16 articles, 10 of which suggested specific at-risk populations for screening. The European Society of Cardiology recommends to screen patients with a wall thickness ≥12 mm and heart failure, aortic stenosis, or red flag symptoms, especially if they are >65 years. The underlying evidence was generally good for diagnosis, while significant gaps were identified for the relevance and mutual ranking of the different suspicion criteria and for systematic screening. Conclusively, patient entry was neglected in the reviewed literature. While multiple red flags were described, high-quality prospective studies designed to evaluate their suitability as suspicion criteria were lacking. An upcoming task lies in defining and evaluating at-risk populations for screening. All are steps needed to promote early detection and diagnosis of ATTRwt CM, a prerequisite for timely treatment.

Utility and pitfalls of the electrocardiogram in the evaluation of cardiac amyloidosis

BACKGROUND

Cardiac amyloidosis is a protein misfolding disorder involving deposition of amyloid fibril proteins in the heart. The associated fibrosis of the conduction tissue results in conduction abnormalities and arrhythmias. "Classical" electrocardiogram (ECG) findings in cardiac amyloidosis include that of low voltage complexes with increased left ventricular wall thickness on echocardiography. However, this "classical" finding is neither sensitive nor specific. As cardiac amyloidosis is associated with a generally poor prognosis, the need for early recognition of this disease is important given the availability of new treatment options. In this review, we highlight 3 cases of patients with cardiac amyloidosis. Although presenting with typical clinical signs and symptoms, ECG for all 3 patients was not consistent with the classical findings described. They underwent further diagnostic tests which clinched the diagnosis of cardiac amyloidosis, allowing patients to receive targeted treatment. Through the review of the literature, we will highlight the different ECG patterns in patients with different types of cardiac amyloidosis and clinical scenarios, as well as the pitfalls of using ECG to identify the condition. Lastly, we also emphasize the current paradigms in diagnosing cardiac amyloidosis through the non-invasive methods of echocardiography, cardiac magnetic resonance imaging, and nuclear technetium-pyrophosphate imaging.

CONCLUSIONS

Electrocardiogram is often the first investigation used in evaluating many cardiac disorders, including cardiac amyloidosis. However, classical features of cardiac amyloidosis on ECG are often not present. A keen understanding on the ECG features of cardiac amyloidosis and knowledge of the diagnostic workflow is important to diagnose this condition.

New Advanced Imaging Parameters and Biomarkers-A Step Forward in the Diagnosis and Prognosis of TTR Cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative disorder characterized by extracellular myocardial deposits of amyloid fibrils, with poor outcome, leading to heart failure and death, with significant treatment expenditure. In the era of a novel therapeutic arsenal of disease-modifying agents that target a myriad of pathophysiological mechanisms, timely and accurate diagnosis of ATTR-CM is crucial. Recent advances in therapeutic strategies shown to be most beneficial in the early stages of the disease have determined a paradigm shift in the screening, diagnostic algorithm, and risk classification of patients with ATTR-CM. The aim of this review is to explore the utility of novel specific non-invasive imaging parameters and biomarkers from screening to diagnosis, prognosis, risk stratification, and monitoring of the response to therapy. We will summarize the knowledge of the most recent advances in diagnostic, prognostic, and treatment tailoring parameters for early recognition, prediction of outcome, and better selection of therapeutic candidates in ATTR-CM. Moreover, we will provide input from different potential pathways involved in the pathophysiology of ATTR-CM, on top of the amyloid deposition, such as inflammation, endothelial dysfunction, reduced nitric oxide bioavailability, oxidative stress, and myocardial fibrosis, and their diagnostic, prognostic, and therapeutic implications.

[Cardiac arrhythmias and amyloidosis]

Cardiac amyloidosis (CA) is a form of cardiomyopathy characterized by the extracellular deposit of protein fibers in the myocardium, leading to the development of heart failure, arrhythmias, and electrical conduction system alterations. It is known that most cardiomyopathies have a close relationship with heart rhythm abnormalities, however, CA is specially related to different kinds of arrhythmias even in pre-diagnosis stages. Arrhythmias like atrial fibrillation are present in up to 70% of patients with CA associated with a high risk of cardioembolic complications independent of the risk stratification. Ventricular arrhythmias are frequent, but the use of implantable cardioverter defibrillator has not been demonstrated to improve survival. The Atrial-Ventricular node disease is also common, and is frequently associated with the implantation of a pacemaker, even in asymptomatic patients. In this review, we clarify the recommendations of the most current guidelines, summarize historical and contemporaneous data and describe evidence-based strategies for the management of arrhythmias and their complications in CA.

Multimodality Imaging in the Evaluation and Prognostication of Cardiac Amyloidosis

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy resulting from deposition of misfolded immunoglobulin light chains (AL-CA) or transthyretin (ATTR-CA) proteins in the myocardium. Survival varies between the different subtypes of amyloidosis and degree of cardiac involvement, but accurate diagnosis is essential to ensure initiation of therapeutic interventions that may slow or potentially prevent morbidity and mortality in these patients. As there are now effective treatment options for CA, identifying underlying disease pathogenesis is crucial and can be guided by multimodality imaging techniques such as echocardiography, magnetic resonance imaging, and nuclear scanning modalities. However, as use of cardiac imaging is becoming more widespread, understanding optimal applications and potential shortcomings is increasingly important. Additionally, certain imaging modalities can provide prognostic information and may affect treatment planning. In patients whom imaging remains non-diagnostic, tissue biopsy, specifically endomyocardial biopsy, continues to play an essential role and can facilitate accurate and timely diagnosis such that appropriate treatment can be started. In this review, we examine the multimodality imaging approach to the diagnosis of CA with particular emphasis on the prognostic utility and limitations of each imaging modality. We also discuss how imaging can guide the decision to pursue tissue biopsy for timely diagnosis of CA.

Clinical Clues and Diagnostic Workup of Cardiac Amyloidosis

Cardiac amyloidosis is increasingly recognized as an underlying cause of left ventricular wall thickening, heart failure, and arrhythmia with variable clinical presentation. Due to the subtle cardiac findings in early transthyretin cardiac amyloidosis and the availability of therapies that can modify but not reverse the disease progression, early recognition is vital. In light chain amyloidosis, timely diagnosis and treatment can significantly improve survival. In this manuscript, we review the clinical, imaging, and electrocardiographic clues that should raise suspicion for cardiac amyloidosis and provide a simplified diagnostic workup algorithm that ensures an accurate diagnosis. The evolution of the noninvasive diagnosis of cardiac amyloidosis has significantly influenced our understanding of disease prevalence, presentations, and outcomes. However, clinical recognition of clues and red flags remains the most important factor in advancing the care of patients with cardiac amyloidosis.

Electrocardiographic features and need for pacemaker in cardiac amyloidosis: Analysis of 58 cases

AIM

Amyloidosis is a disease in which amyloid fibrils can be deposited in different cardiac structures, and several electrocardiographic abnormalities can be produced by this phenomenon. The objective of this study was to describe the most common basal electrocardiographic alterations in patients diagnosed with cardiac amyloidosis (CA) and to determine if these abnormalities have an impact on the need of pacemaker.

METHODS

This retrospective study included patients who had an established diagnosis of CA [light-chain cardiac amyloidosis (LA-CA) or transthyretin cardiac amyloidosis (TTR-CA)] between January 2013 and March 2021. The baseline heart rate, the percentage of patients with a pseudo-infarct pattern, low-voltage pattern or cardiac conductions disturbances, and the impact of these factors on the need of pacemaker were analysed.

RESULTS

Fifty-eight patients with CA (20 with LA-CA and 38 with TTR-CA) were included, and the majority were male (69.0%). Twenty-one patients had atrial fibrillation (AF) at diagnosis. Thirty-five patients had a pseudo-infarct pattern, 35% had a low-voltage pattern, and 22% had criteria for ventricular hypertrophy. Two hirds had a conduction disorder: 18 patients with first degree atrioventricular block, 12 right bundle branch block, 3 left bundle branch block and 25 with a branch hemiblock. There were no differences between LA-CA and TTR-CA. Patients with TTR-CA had a greater need for pacemakers in the folow-up (39±40 meses). Bundle branch block was a predictor of the need for a permanent pacemaker (HR: 23.43; CI 95%: 4.09.134.09; P=.01).

CONCLUSIONS

Electrocardiographic abnormalities in patients diagnosed wich CA are heterogeneus. Most frecuent is the presence of conduction disorders, the pseudoinfarction pattern, followed by the low voltage pattern. Patients with any bundle branch block at the baseline electrocardiogram need more frecuent to require a pacemaker during follow-up, especially in TTR-CA.

Diagnostic Tools for Cardiac Amyloidosis: A Pragmatic Comparison of Pathology, Imaging and Laboratories

Cardiac amyloidosis (CA) is a complex disease considered to be the most common underdiagnosed form of restrictive cardiomyopathy. Accumulation of misfolded proteins called amyloid fibrils in the extracellular space results in clinical deterioration and late diagnosis is associated with morbidity and mortality. Both types of this disease, light chain CA and transthyretin-related CA share many cardiac and extracardiac features that compromise multiple organs such as kidneys, musculoskeletal system, autonomic nervous system, and gastrointestinal tract. Early diagnosis and detection of CA are imperative. Clinicians should maintain a high degree of suspicion among patients with unexplained diastolic heart failure to implement different disease-altering therapies at the early stages of the disease. In this article, we provided a comprehensive review of multiple invasive and non-invasive cardiac imaging modalities with their respective degrees of sensitivities and specificity.