Accidental Hypothermia-Induced J Wave Coupled With Giant R Wave Augmented by Premature Atrial Contraction: A Case Report.

The 12-lead electrocardiographic findings in hypothermia include the presence of J waves; prolongation of the PR, QRS, and QT intervals; and atrial and ventricular dysrhythmias. Among these findings, the J wave, known as the Osborn wave, is considered pathognomonic. In 1953, the J wave was reported as a specific response to hypothermia in dogs, representing the current at the site of injury instead of a widening of the QRS complex that occurs caused by a conduction delay. The J wave is often accompanied by ventricular fibrillation. For the past 28 years, it was assumed that the hypothermia-induced J wave was mediated by the transient outward current. However, it was recently been reported that the J waves in some patients with hypothermia can be considered delayed conduction-related waveforms. Here, we present a case of hypothermia-induced J waves together with giant R waves, which have not been previously reported during hypothermia, augmented by short RR intervals arising from premature atrial contractions. Our observations indicate that the underlying mechanism for the genesis of J waves is indeed conduction delay and not transient outward currents.

Downsloping TP Segment in the Precordial Leads on a Standard 12-lead Electrocardiogram: Suspected Cardiac Impulse-tapping Artifact.

We herein report an 80-year-old man showing a downsloping TP segment together with an increase in the height of the T wave in the precordial leads on a standard 12-lead electrocardiogram (ECG). Separately, an 87-year-old woman showed only a downsloping TP segment in the precordial leads on a standard 12-lead ECG. Neither patient reported chest pain or dyspnea when ECGs was obtained. This downsloping TP segment in the precordial leads on the standard 12-lead ECG is thought to be due to a cardiac impulse-tapping artifact. Differential diagnoses are also discussed.

Technetium-99m-pyrophosphate imaging-based computed tomography-guided core-needle biopsy of internal oblique muscle in wild-type transthyretin cardiac amyloidosis.

BACKGROUND: Technetium-99m-pyrophosphate (99mTc-PYP) uptake in the internal oblique muscle (IOM), which is often observed in patients with wild-type transthyretin cardiac amyloidosis (ATTR-CA), indicates amyloid transthyretin (ATTR) deposition. OBJECTIVE: This study aimed to assess the safety and efficacy of 99mTc-PYP imaging-based computed tomography (CT)-guided core-needle biopsy of the IOM as a new extracardiac screening biopsy for confirming the presence of ATTR deposits. METHODS: Patients with suspected ATTR-CA in whom myocardial tracer uptake was detected on chest- and abdomen-centered images of 99mTc-PYP scintigraphy underwent CT-guided core-needle biopsy at the site with the highest tracer uptake in the IOM between September 2021 and November 2022. RESULTS: All 18 consecutive patients (mean age, 86.3 years ± 6.5; 61.1% male) enrolled in the study showed 99mTc-PYP uptake into the IOM. Adequate tissue samples were obtained from all patients except one without serious complications. Immunohistochemical analysis confirmed ATTR deposits in 16/18 (88.9%) patients. In the remaining two patients, ATTR deposits were observed via endomyocardial biopsy. All patients were diagnosed with wild-type ATTR-CA based on transthyretin gene sequence testing results. CONCLUSION: In wild-type ATTR-CA, 99mTc-PYP imaging-based CT-guided core-needle biopsy of the IOM could be used as an extracardiac screening biopsy to confirm the presence of ATTR deposits.

Identification of the Vessels Causing Myocardial Ischemia by a Synthesized 18-Lead Electrocardiogram Obtained After the Master Two-Step Exercise Test in a Patient With Effort Angina.

A synthesized 18-lead electrocardiograph is a specialized technology that mathematically computes the virtual electrocardiographic waveforms of the right chest leads (V3R, V4R, and V5R) and posterior leads (V7, V8, and V9) based on a standard 12-lead electrocardiograph input without additional lead placement or techniques. Synthesized 18-lead electrocardiography is a useful test for the identification of the culprit coronary arteries in patients with ST-segment elevation myocardial infarction of the right ventricular wall or the posterior/lateral left ventricular wall, which are often missed on standard 12-lead electrocardiography. However, few studies have examined the usefulness of this modality during exercise stress testing. We present a case of a 78-year-old man with a two-month history of typical angina. The synthesized 18-lead electrocardiogram obtained just after the Master two-step exercise test revealed ST-segment shifts in multiple leads, including synthesized V4R, V5R, and V7-9 leads, and U-wave changes in some leads, including the synthesized V9 lead. The diagnosis of the culprit coronary arteries causing exercise-induced myocardial ischemia is discussed with reference to coronary angiographic findings. This modality could potentially increase the sensitivity and specificity for the detection of coronary artery disease and accurately pinpoint the site of the lesion. If an electrocardiograph can display a synthesized 18-lead electrocardiogram, it should be used when evaluating the waveform due to myocardial ischemia.

A Gluteus Medius Muscle Biopsy to Confirm Amyloid Transthyretin Deposition in Wild-type Transthyretin Cardiac Amyloidosis: A Report of Two Cases.

In patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), the uptake of the tracer on technetium-99m-labeled pyrophosphate (99mTc-PYP) scintigraphy, which indicates amyloid transthyretin (ATTR) per se, is often observed in skeletal muscles, such as the abdominal oblique and gluteal muscles. Among extracardiac biopsies for confirming ATTR deposition in ATTRwt-CA, a 99mTc-PYP imaging-based computed tomography (CT)-guided core needle biopsy of the internal oblique muscle has relatively high sensitivity. In some patients, the 99mTc-PYP uptake is more pronounced in the gluteal muscles than in oblique muscles. We herein report two cases of ATTRwt-CA in which a CT-guided biopsy of the gluteus medius muscle with 99mTc-PYP uptake confirmed the presence of ATTR deposits.

99mTc-Pyrophosphate Scintigraphy Can Image Tracer Uptake in Skeletal Trunk Muscles of Transthyretin Cardiac Amyloidosis.

PURPOSE: 99mTc-pyrophosphate (99mTc-PYP) uptake in the skeletal muscles is minimal in patients with transthyretin cardiac amyloidosis (ATTR-CA) when assessed qualitatively and quantitatively. We previously demonstrated moderate- to high-grade 99mTc-PYP uptake in the subcutaneous abdominal fat of some patients with ATTR-CA and showed that this abnormal finding could reflect the regional amyloid burden of this tissue. We aimed to investigate the frequency of 99mTc-PYP uptake in skeletal trunk muscles of patients with ATTR-CA. METHODS: Chest- and abdomen-centered 99mTc-PYP scintigraphy images were obtained 2 hours after IV injections of the tracer (20 mCi) in 36 patients with ATTR-CA. The frequency of 99mTc-PYP uptake in the following 11 skeletal trunk muscles was investigated: pectoralis major, deltoid, subscapularis, infraspinatus, trapezius, latissimus dorsi, erector spinae, psoas major, abdominal oblique, rectus abdominis, and the gluteus muscles. RESULTS: Ten of the 11 muscles were involved in patients with the highest number of 99mTc-PYP uptake in the skeletal trunk muscles examined, whereas no muscle was involved in a patient with the least uptake. The muscle with the highest rate of 99mTc-PYP uptake, observed in 34 of 36 patients (94.4%), was the abdominal oblique. No tracer uptake was observed in the psoas major. The frequency of radiotracer uptake in the remaining examined muscles was between those of abdominal oblique and psoas major muscles. CONCLUSIONS: Radiotracer uptake was often detectable in some skeletal trunk muscles of ATTR-CA, although the muscles of patients examined and the skeletal trunk muscles of 1 patient showed heterogeneity in the uptake of 99mTc-PYP.

Amyloid deposit corresponds to technetium-99m-pyrophosphate accumulation in abdominal fat of patients with transthyretin cardiac amyloidosis.

BACKGROUND: Radionuclide imaging using bone-avid tracers plays a critical role in diagnosing transthyretin cardiac amyloidosis (ATTR-CA), but technetium-99m-pyrophosphate (PYP) rarely allows the detection of extracardiac amyloid infiltration. We retrospectively investigated the frequency of PYP uptake in the subcutaneous abdominal fat of patients with ATTR-CA and its relevance to the results of fine-needle aspiration biopsy (FNAB) of this tissue. METHODS: Chest-centered images of PYP scintigraphy were obtained 2 h after the intravenous injection of the tracer (20 mCi), and the frequency of PYP uptake in the subcutaneous abdominal fat was evaluated. Amyloid deposits of fat smears taken by subcutaneous abdominal fat FNAB were assessed by Congo red staining. RESULTS: Twenty-four patients with ATTR-CA were included. Ten (41.7%) patients showed some PYP uptake in the subcutaneous abdominal fat (positive PYP group), and 14 patients did not (negative PYP group). Amyloid deposits were detected by subcutaneous abdominal fat FNAB in 7/10 patients (70.0%) of the positive PYP group versus 0/14 patients (0%) of the negative PYP group, and the difference was significant. CONCLUSIONS: In patients with ATTR-CA, abnormal PYP uptake in the subcutaneous abdominal fat could reflect the regional amyloid deposition confirmed by FNAB of this tissue.

Prognostic assessment of relative apical sparing pattern of longitudinal strain for severe aortic valve stenosis.

BACKGROUNDS: The relative apical sparing pattern (RASP) of left ventricular (LV) longitudinal strain (LS) is frequently associated with cardiac amyloidosis. Elderly patients with aortic valve stenosis (AS) complicated by transthyretin amyloid cardiomyopathy have poor prognosis. Furthermore, deteriorated basal LS in AS patients has been reported to be associated with adverse outcome. We investigated the association between RASP and outcomes in patients with severe AS. METHODS: We retrospectively studied 156 consecutive patients with severe AS and preserved LV ejection fraction. RASP was assessed by both of semi-quantitative (sRASP) and quantitative (qRASP) methods. sRASP was defined as a deterioration of LS (≥-10%) in ≥ 5 (of 6) basal segments, relative to preserved LS (<-15%) in at least 1 apical segment. qRASP was calculated using the following formula: average apical LS/(average basal LS + average mid-ventricle LS); qRASP ≥ 1 was defined as positive. Patients were followed up to determine outcomes, which included sudden cardiac death or unexpected admission due to heart failure, over a median of 1.9 years. RESULTS: sRASP and qRASP were assessed in all patients, but 24 and 42 patients fulfilled the criteria for sRASP and qRASP, respectively. Both assessments were significantly associated with outcomes (n = 44; 28%). Furthermore, sRASP was significantly associated with outcome after adjusting for EuroSCORE, NYHA ≥ II, or global longitudinal strain. A model based on these covariates for predicting outcomes significantly improved by adding sRASP. CONCLUSION: RASP is observed in some patients with severe AS and provides additive prognostic information over conventional parameters.

Prognostic value of proximal left coronary artery flow velocity detected by transthoracic Doppler echocardiography.

BACKGROUND: Lesions in the proximal left coronary artery (LCA) are associated with a poor prognosis compared with other lesional sites. Transthoracic Doppler echocardiography (TTDE) can help to detect proximal LCA flow, and an accelerated coronary flow velocity (CFV) indicates the presence of proximal LCA lesions. This study aimed to investigate the prognostic value of CFV in the proximal LCA measured by TTDE. METHODS: We enrolled 1472 consecutive hemodynamically stable patients with known or suspected heart disease whose CFV was successfully detected using TTDE accompanied by routine echocardiography between 2008 and 2011. The primary outcome was cardiac death (acute myocardial infarction, heart failure, or sudden cardiac death) and patients were followed up over a median of 6.3 years. RESULTS: Overall, 42 cardiac deaths (3%) were observed. An increased CFV was significantly associated with the outcome in several models based on potential confounders (age, rate pressure product, Framingham Risk Score, diabetes, coronary artery disease, hemoglobin, brain natriuretic peptide, estimated glomerular filtration rate, left ventricular mass, left ventricular ejection fraction, and E/e'). Using a receiver operating characteristic curve analysis, the optimal cut-off value for the CFV to the association of the outcome was 37 cm/s (area under the curve, 0.70; sensitivity, 82%; specificity, 62%). In sequential Cox proportional hazards models, the CFV added incremental prognostic information to the clinical and basic echocardiographic parameters (chi-squared: 110.7 to 146.6, P < 0.01). CONCLUSIONS: An increased CFV in the proximal LCA was associated with cardiac death, incremental to the clinical and basic echocardiographic parameters.

Relationship between augmentation index and left ventricular diastolic function in healthy women and men.

BACKGROUND: The aim of this study was to investigate the effect of sex on the correlation between arterial stiffness and left ventricular (LV) diastolic function in a healthy population without significant atherosclerosis. METHODS: Subjects (n = 446) who had simultaneous echocardiography and arterial stiffness recordings were enrolled. From these subjects, 95 men and 72 age-matched women without atherosclerotic risk factors (hypertension, dyslipidemia, and diabetes mellitus) were included in the analysis. We measured brachial-ankle pulse wave velocity (baPWV) and carotid augmentation index (AIx) as arterial stiffness parameters. RESULTS: Peak early diastolic mitral annular velocity (e') was significantly correlated with baPWV (men: r = -0.428, P < 0.001; women: r = -0.515, P < 0.001) and carotid AIx (men: r = -0.295, P = 0.004; women: r = -0.558, P < 0.001). The ratio of early diastolic mitral flow velocity to e' (E/e') was significantly correlated with both arterial stiffness parameters in women but not men. Multivariable regression analysis revealed carotid AIx (ß = -0.257; P = 0.02) was a significant independent predictor of e' in women but not men. CONCLUSIONS: These results suggest that the correlation between AIx and LV diastolic function is stronger in women than men in a healthy population.

Role of transthoracic Doppler echocardiography in patients with a proximal left coronary artery lesion that cannot be diagnosed by computed tomography angiography.

The diagnosis of lesions with severe calcium or in-stent stenosis using coronary computed tomography angiography (CCTA) is still difficult. The aim of the present study was to evaluate the accuracy of transthoracic Doppler echocardiography (TTDE) in patients with suspected angina pectoris, who had a proximal left coronary artery (LCA) site that could not be evaluated by CCTA. Fifty-eight patients were evaluated. The proximal LCA was defined as the left main coronary artery and proximal left anterior descending coronary artery. All patients underwent TTDE and had coronary angiography performed as a reference method. We measured the proximal left coronary flow velocity (CFV) by both color and pulse Doppler methods. Proximal coronary flow was detected in 45 (78%) of 58 patients. CFVs measured by both methods were significantly greater in the group with severe stenosis (percent diameter stenosis >70%) than in the groups with moderate stenosis (percent diameter stenosis 40% to 70%) or without stenosis (color Doppler: 148 ± 42 cm/s, 89 ± 40 cm/s, and 41 ± 22 cm/s, respectively, p <0.05; pulse Doppler: 143 ± 61 cm/s, 82 ± 33 cm/s, and 39 ± 17 cm/s, respectively, p <0.05). Receiver operating characteristic curve analysis showed that the optimal CFV cut-off values obtained by color and pulse Doppler to diagnose severe stenosis were 92 cm/s (sensitivity, 100%; specificity, 90%) and 81 cm/s (sensitivity, 100%; specificity, 85%), respectively. In conclusion, TTDE could diagnose proximal LCA stenosis with good accuracy in patients who could not be evaluated by CCTA.

Clinical significance of global two-dimensional strain as a surrogate parameter of myocardial fibrosis and cardiac events in patients with hypertrophic cardiomyopathy.

AIMS: Late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (MRI) in hypertrophic cardiomyopathy (HCM) has been reported to be associated with myocardial fibrosis and cardiac events. In patients with HCM, two-dimensional (2D) strain can identify subclinical global systolic dysfunction despite normal left ventricular (LV) chamber function. Therefore, this study tested the hypothesis that global 2D strain could detect subtle myocardial fibrosis and serve as a novel prognostic parameter in HCM patients. METHODS AND RESULTS: Echocardiography and MRI were performed in 48 consecutive patients with HCM and normal chamber function. We measured global longitudinal strain (GLS) in apical two-chamber, four-chamber, and long-axis views using speckle-tracking analysis. The extent of LGE (%LGE = LGE volume/total LV volume) and LV mass index were calculated by MRI using Simpson's rule and custom software. All patients were followed up for major cardiac events. Global longitudinal strain in patients with LGE was significantly lower than that without LGE (-11.8 ± 2.8 vs. -15.0 ± 1.7%, P < 0.001). Multivariate analysis showed that GLS was an independent predictor of %LGE (standard coefficient = 0.627, P < 0.001). During a mean follow-up period of 42 ± 12 months, five patients had cardiac events. When the patients were stratified based on the median level of GLS (-12.9%), all events were observed in the worse GLS group (P = 0.018). CONCLUSION: These results suggest that global 2D strain might provide useful information on myocardial fibrosis and cardiac events in HCM patients with normal chamber function.