Patient acceptance of subcutaneous versus transvenous defibrillator systems: A multi-center experience.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an effective alternative to the transvenous ICD. No study has yet compared S-ICD and transvenous ICD by assessing patient acceptance as a patient-centered outcome. OBJECTIVE: To evaluate the patient acceptance of the S-ICD and to investigate its association with clinical and implantation variables. In patients with symptomatic heart failure and reduced ejection fraction (HFrEF), the acceptance of the S-ICD was compared with a control group of patients who received a transvenous ICD. METHODS: Patient acceptance was calculated with the Florida Patient Acceptance Survey (FPAS) which measures four factors: return to function (RTF), device-related distress (DRD), positive appraisal (PA), and body image concerns (BIC). The survey was administered 12 months after implantation. RESULTS: 176 patients underwent S-ICD implantation. The total FPAS and the single factors did not differ according to gender, body habitus, or generator positioning. Patients with HFrEF had lower FPAS and RTF. Younger patients showed better RTF (75 [56-94] vs. 56 [50-81], p = .029). Patients who experienced device complications or device therapies showed higher DRD (40 [35-60] vs. 25 [10-50], p = .019). Patients with HFrEF receiving the S-ICD had comparable FPAS, RTF, DRD, and BIC to HFrEF patients implanted with the transvenous ICD while exhibited significantly better PA (88 [75-100] vs. 81 [63-94], p = .02). CONCLUSIONS: Our analysis revealed positive patient acceptance of the S-ICD, even in groups at risk of more distress such as women or patients with thinner body habitus, and regardless of the generator positioning. Among patients receiving ICDs for HFrEF, S-ICD was associated with better PA versus transvenous ICD.

Implantation technique and optimal subcutaneous defibrillator chest position: a PRAETORIAN score-based study.

AIMS: The traditional technique for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation involves three incisions and a subcutaneous pocket. Recently, a two-incision and intermuscular (IM) technique has been adopted. The PRAETORIAN score is a chest radiograph-based tool that predicts S-ICD conversion testing. We assessed whether the S-ICD implantation technique affects optimal position of the defibrillation system according to the PRAETORIAN score. METHODS AND RESULTS: We analysed consecutive patients undergoing S-ICD implantation. The χ2 test and regression analysis were used to determine the association between the PRAETORIAN score and implantation technique. Two hundred and thirteen patients were enrolled. The S-ICD generator was positioned in an IM pocket in 174 patients (81.7%) and the two-incision approach was adopted in 199 (93.4%). According to the PRAETORIAN score, the risk of conversion failure was classified as low in 198 patients (93.0%), intermediate in 13 (6.1%), and high in 2 (0.9%). Patients undergoing the two-incision and IM technique were more likely to have a low (<90) PRAETORIAN score than those undergoing the three-incision and subcutaneous technique (two-incision: 94.0% vs. three-incision: 78.6%; P = 0.004 and IM: 96.0% vs. subcutaneous: 79.5%; P = 0.001). Intermuscular plus two-incision technique was associated with a low-risk PRAETORIAN score (hazard ratio 3.76; 95% confidence interval 1.01-14.02; P = 0.04). Shock impedance was lower in PRAETORIAN low-risk patients than in intermediate-/high-risk categories (66 vs. 96 Ohm; P = 0.001). The PRAETORIAN score did not predict shock failure at 65 J. CONCLUSION: In this cohort of S-ICD recipients, combining the two-incision technique and IM generator implantation yielded the lowest PRAETORIAN score values, indicating optimal defibrillation system position. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/ Identifier: NCT02275637.

Optimization of coronary sinus lead placement targeted to right-to-left delay in patients undergoing cardiac resynchronization therapy.

AIMS: Anatomical placement of the coronary sinus (CS) lead in basal or mid-ventricular positions of the posterior and lateral walls is associated with a better clinical outcome of cardiac resynchronization therapy (CRT). We hypothesized that optimization of CS lead placement targeted the right-to-left electrical delay (RLD) predicts an additional clinical benefit. METHODS AND RESULTS: The CS lead was placed according to current standards in 90 patients (Conventional group) and at the site of the longest RLD in 121 patients (RLD group). Non-responders were defined as those who died or underwent hospitalization for heart failure or did not improve in their Clinical Composite Score within 6 months. There were 67 (32%) non-responders. Compared with Conventional group, the final CS pacing site was more frequently in the basal segments in the RLD group (40% vs. 23%, P = 0.007); moreover, the RLD ratio (%RLD) of the total QRS width was longer (77 ± 13 vs. 73 ± 15, P = 0.05) and biventricular QRS shortened more from the baseline (-31 ± 21 ms vs. -21 ± 26 ms, P = 0.004). Nevertheless, the rate of non-responders was similar in the RLD and Conventional groups (35% vs. 28%, P = 0.30), as was %RLD (76 ± 16 vs. 75 ± 13, P = 0.66). QRS width during right ventricular (RV) pacing was an independent predictors of adverse outcome, with a 2% increase in the risk of failure for each 1 ms increase in QRS (P = 0.006). CONCLUSION: Optimization of CS lead placement targeted to latest electrical activation does not provide additional clinical benefit to anatomical placement in basal or mid-ventricular positions of the posterior and lateral walls. QRS width during RV pacing was a strong predictor of CRT failure. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT03204864.

Access to magnetic resonance imaging of patients with magnetic resonance-conditional pacemaker and implantable cardioverter-defibrillator systems: results from the Really ProMRI study.

Aims: The Really ProMRI study evaluates magnetic resonance imaging (MRI) access for patients with cardiac implantable electronic devices (CIEDs) as well as the performance of magnetic resonance (MR)-conditional leads when undergoing MRI. Methods and results: Patients either with an MR-conditional pacemaker or implantable defibrillator (ICD) system or with at least a component (device or one or more leads) from an MR-conditional system, were asked to fill in a questionnaire when they were referred to a MR scan. The rate of prescription, denial, or execution of MR examinations was evaluated in a 1-year follow-up visit. In total, 555 patients [median age (interquartile range) 72.2 (62.2-78.6); 72% male] were enrolled, 49% (270) with a pacemaker, 51% (285) with an ICD system. Five-hundred and ten patients completed the follow-up period. A total of 37 MRI referrals were reported in 35 patients, with a consequent event rate of 7.0/100 patient-years (CI, 4.9-9.7). Fourteen were denied, while 23 [66%; (CI, 48-81%)] were performed. The number of patients with MR referrals was not statistically different between pacemaker and ICD groups (21 vs. 14; P = 0.178). The rate of scans performed was higher in the pacemaker subjects (19/23 vs. 4/14, P = 0.003), while it was similar between patients with or without a complete MR-conditional system (19/30 vs. 4/7, P = 0.606). Conclusion: In this study, we reported a 7.0/100 patient-year's event rate of MR prescriptions in CIED patients. Many examinations were denied, despite MR-conditional systems, especially in ICD patients. Regulatory and cultural changes are needed to allow wider access to MR imaging in CIED patients with MR-conditional systems.

Optimization of coronary sinus lead placement targeted to the longest right-to-left delay in patients undergoing cardiac resynchronization therapy: The Optimal Pacing SITE 2 (OPSITE 2) acute study and protocol.

AIMS: Left ventricular (LV) lead positioning at the site of delayed electrical activation is associated with better response to cardiac resynchronization therapy (CRT). We hypothesized that a long electrical conduction delay between right ventricular (RV) and coronary sinus (CS) leads during RV pacing (RLD index) is correlated with a better clinical outcome METHODS AND RESULTS: RLD is measured intraprocedurally, during RV pacing, as the time interval between the intracardiac electrograms of RV and CS leads. Initially, we did a prove-of-concept, feasibility, acute study in 97 patients who underwent CRT implantation. The CS lead position was assessed in the 40° right anterior oblique and 40° left anterior oblique views and assigned to one of 11 prespecified segments of a schematic eyeball depiction of the LV walls. Acute outcomes were QRS width during biventricular (BIV) pacing. The longest RLD were found in the basal and mid lateral segments; these accounted for 82% and 78%, respectively, of the total QRS width (%RLD). %RLD was inversely correlated with BIV-paced QRS (P  =  0.0001). A similar slope was present either in the 78 patients with preserved atrioventricular (AV) conduction and in the 19 without AV conduction (- 0.34 vs - 0.27, P  =  0.7). CONCLUSION: We showed that RLD can be used to guide lead placement at the time of CRT implantation and that it is correlated with BIV-QRS width, an indirect predictor of clinical outcome. Based on these findings we started the prospective, multicenter Optimal Pacing SITE 2 (OPSITE 2) trial with the objective to demonstrate a relationship between RLD and clinical outcomes assessed as death, hospitalization for heart failure, New York Heart Association class, and clinical composite score. The protocol is provided.

Automatic management of atrial and ventricular stimulation in a contemporary unselected population of pacemaker recipients: the ESSENTIAL Registry.

AIMS: We investigated the applicability of the Ventricular Capture Control (VCC) and Atrial Capture Control (ACC) algorithms for automatic management of cardiac stimulation featured by Biotronik pacemakers in a broad, unselected population of pacemaker recipients. METHODS AND RESULTS: Ventricular Capture Control and Atrial Capture Control were programmed to work at a maximum adapted output voltage as 4.8 V in consecutive recipients of Biotronik pacemakers. Ambulatory threshold measurements were made 1 and 12 months after pacemaker implant/replacement in all possible pacing/sensing configurations, and were compared with manual measurements. Among 542 patients aged 80 (73-85) years, 382 had a pacemaker implant and 160 a pacemaker replacement. Ventricular Capture Control could work at long term in 97% of patients irrespectively of pacing indication, lead type, and lead service life, performance being superior with discordant pacing/sensing configurations. Atrial Capture Control could work in 93% of patients at 4.8 V maximum adapted voltage and at any pulse width, regardless of pacing indication, lead type, and service life. At 12-month follow-up, a ventricular threshold increase ≥1.5 V had occurred in 4.4% of patients uneventfully owing to VCC functioning. Projected pacemaker longevity at 1 month was strongly correlated with the 12-month estimate, and exceeded 13 years in >60% of patients. CONCLUSION: These algorithms for automatic management of pacing output ensure patient safety in the event of a huge increase of pacing threshold, while enabling maximization of battery longevity. Their applicability is quite broad in an unselected pacemaker population irrespectively of lead choice and service of life.

Prolonged care delivery time and reduced rate of electrophysiological procedures during the lockdown period due to Covid-19 outbreak.

OBJECTIVES: The aim of this study is to demonstrate how Electrophysiology activity has been impacted by the pandemic Coronavirus disease 2019 (COVID-19). METHODS: In this multicenter retrospective study, we analyze all consecutive patients admitted for electrophysiological procedures during the COVID-19 lockdown in the Tuscany region of Italy, comparing them to patients hospitalized in the corresponding period of the previous year. RESULTS: The impact of COVID-19 on cardiac arrhythmia management was impressive, with a reduction of more than 50% in all kinds of procedures. A gender gap was observed, with a more relevant reduction for female patients. Arrhythmic urgencies requiring a device implant showed a reduced time from symptoms to first medical contact but the time from first medical contact to procedure was significantly prolonged. CONCLUSION: Hospitals need to consider how outbreaks may affect health systems beyond the immediate infection. Routine activity should be based on a risk assessment between the prompt performance of procedure and its postponement. Retrospective observational analysis such as this study could be decisive in evidence-based medicine of any future pathogen outbreak.Nonstandard Abbreviations and Acronyms PM= pacemakerICD= implantable cardioverter defibrillatorECV= electrical cardioversionEPS= electrophysiological studyAP= ablations proceduresCIED= cardiac implantable electronic devicesWCD= wearable cardioverter defibrillatorEP Lab= Electrophysiology LaboratoriesAVNRT =atrioventricular nodal reentry tachycardiaAVRT= atrioventricular reentry tachycardiaAFL= atrial flutterAF= atrial fibrillationVT= ventricular tachycardiaAT= atrial tachycardia.

Impact of pacemaker longevity on expected device replacement rates: Results from computer simulations based on a multicenter registry (ESSENTIAL).

BACKGROUND: The rate of device replacement in pacemaker recipients has not been investigated in detail. HYPOTHESIS: Current pacemakers with automatic management of atrial and ventricular pacing output provide sufficient longevity to minimize replacement rate. METHODS: We considered a cohort of 542 pacemaker patients (age 78 ± 9 years, 60% male, 71% de-novo implants) and combined 1-month projected device longevity with survival data and late complication rate in a 3-state Markov model tested in several Monte Carlo computer simulations. Predetermined subgroups were: age < or ≥ 70; gender; primary indication to cardiac pacing. RESULTS: At the 1-month follow-up the reported projected device longevity was 153 ± 45 months. With these values the proportion of patients expected to undergo a device replacement due to battery depletion was higher in patients aged <70 (49.9%, range 32.1%-61.9%) than in age ≥70 (24.5%, range 19.9%-28.8%); in women (39.9%, range 30.8%-48.1%) than in men (32.0%, range 24.7%-37.5%); in sinus node dysfunction (41.5%, range 30.2%-53.0%) than in atrio-ventricular block (33.5%, range 27.1-38.8%) or atrial fibrillation with bradycardia (27.9%, range 18.5%-37.0%). The expected replacement rate was inversely related to the assumed device longevity and depended on age class: a 50% increase in battery longevity implied a 5% reduction of replacement rates in patients aged ≥80. CONCLUSIONS: With current device technology 1/4 of pacemaker recipients aged ≥70 are expected to receive a second device in their life. Replacement rate depends on age, gender, and primary indication owing to differences in patients' survival expectancy. Additional improvements in device service time may modestly impact expected replacement rates especially in patients ≥80 years.

Incremental value of ultrasonic tissue characterization (backscatter) in the evaluation of left ventricular myocardial structure and mechanics in essential arterial hypertension.

BACKGROUND: Ultrasonic backscatter parameters were analyzed in hypertensive patients and divided into groups according to both severity of left ventricular hypertrophy (LVH) (group A: no LVH [n=52]; B: mild to moderate LVH [n=55]; and C: severe LVH [n=10]) and left ventricular geometry (normal geometry [n=44]; concentric remodeling [n=8]; concentric hypertrophy [n=25]; and eccentric hypertrophy [n=40]). METHODS AND RESULTS: We studied 117 male, essential hypertensive patients and 19 normotensive, age-matched (40+/-5 years), healthy subjects who served as controls. Ambulatory and office blood pressure measurements were taken and 2-dimensional Doppler echocardiography and ultrasonic myocardial integrated backscatter (IBS) were performed. A group from the hypertensive study population (n=16) was observed after a period of pharmacological antihypertensive treatment to determine the behavior of backscatter parameters in relation to eventual regression of left ventricular mass (LVM). The cyclic variation index (CVIs) of the backscatter signal at the septum level was grouped according to each LVM level and was 29.4+/-9.3 (controls), 15+/-11 (group A), 9.5+/-10 (group B), and -1.5+/-8.6 (group C) (P<0.001). CVI septum values grouped according to left ventricular geometry were 15+/-11 (normal geometry), 12+/-7 (concentric remodeling), 7+/-11 (concentric hypertrophy), and 7.8+/-11 (eccentric hypertrophy) (P<0.01). Follow-up data demonstrate a significant reduction of LVM after therapy, as well as a significant increase in CVIs toward normal values. CONCLUSIONS: Hypertensive patients with higher LVM had the worst prognosis; in fact, those patients had the most significant CVI alterations. Regression of LVM subsequent to chronic pharmacological therapy induces a normalization of ultrasonic backscatter parameters. Ultrasonic tissue characterization (backscatter) analysis could allow early identification of patients at risk of developing complications of hypertensive cardiopathy.

Severe aortic stenosis and myocardial function: diagnostic and prognostic usefulness of ultrasonic integrated backscatter analysis.

BACKGROUND: The aim of this study was to assess the myocardial reflectivity pattern in severe aortic valve stenosis through the use of integrated backscatter (IBS) analysis. Patients with aortic stenosis (AS) were carefully selected in the Department of Cardiology. METHODS AND RESULTS: Thirty-five subjects (AS: valve orifice < or =1 cm2; 12 female; mean age, 71.8+/-6.2 years) and 25 healthy subjects were studied. All subjects of the study had conventional 2D-Doppler echocardiography and IBS. Backscatter signal was sampled at the septum and posterior wall levels. Patients with AS were divided into 2 groups: 16 patients with initial signs of congestive heart failure and a depressed left ventricular systolic function (DSF) (ejection fraction [EF] range, 35% to 50%) and 19 asymptomatic patients with normal left ventricular systolic function (NSF) (EF >50%). Myocardial echo intensity (pericardium related) was significantly higher at the septum and posterior wall levels in DSF than in NSF and in control subjects. IBS variation, as an expression of variation of the signal, appeared to be significantly lower in AS with DSF than in NSF and in control subjects, at both the septum and posterior wall levels. Patients with DSF underwent aortic valve replacement, and, during surgical intervention, a septal myocardial biopsy was made for evaluation of myocardium/fibrosis ratio. Abnormally increased echo intensity was detected in left ventricular pressure overload by severe aortic stenosis and correlated with increase of myocardial collagen content (operating biopsy). CONCLUSIONS: One year after aortic valve replacement, we observed a significant reduction of left ventricular mass, and, only if pericardial indexed IBS value (reduction of interstitial fibrosis) decreased, it was possible to observe an improvement of EF and of IBS variation.

Myocardial function in severe aortic stenosis before and after aortic valve replacement: a Doppler tissue imaging study.

BACKGROUND: The aim of the study was to assess the value of Pulsed-wave Doppler tissue imaging (DTI) in assessing diastolic and systolic function in patients with severe aortic value stenosis. METHODS: Thirty-five patients with aortic stenosis (AS) (valve orifice < or = 1 cm 2 , mean age 71.8 +/- 6.2) and 35 comparable healthy subjects were studied. All subjects performed conventional 2-dimensional Doppler echocardiography and DTI at mitral annulus level. Patients with AS were divided into 2 groups: 16 patients who presented initial signs of HF and a depressed left ventricular systolic function (AS I) (EF: 35%-50%) and 19 patients were asymptomatic and had normal left ventricular systolic function (EF > 50%) (ASII). The 16 symptomatic AS patients underwent surgical aortic valve replacement and were examined after 1 year. RESULTS: DTI was able to detect abnormalities of systolic and diastolic function in AS: the significantly lower peak S velocity in AS I than in AS II and in controls, both at septum and lateral wall level; the significantly lower peak E velocity in AS I than in AS II and in controls both at septum and lateral wall level; the significantly higher peak A velocity in AS I than in AS II and in controls both at septum and lateral wall level; the significant lower E/A ratio in AS I than in AS II and in controls both at septum and lateral wall level. CONCLUSION: We found a significant inverse correlation between DTI lateral S velocity, DTI peak E velocity, lateral DTI E/A ratio, and AS peak and mean gradient. According to the results of this study we can affirm that DTI parameters surely had an important physiopathological impact in the knowledge of myocardial function in patients with severe aortic stenosis.

Microalbuminuria, a parameter independent of metabolic influences in hypertensive men.

OBJECTIVE: To evaluate the relationship of albuminuria and microalbuminuria (overnight urine albumin > or = 15 micro g/min) with insulin resistance and related metabolic abnormalities in patients with essential hypertension. DESIGN: Cross-sectional evaluation of 271 (age range, 19-77 years) never-treated, non-diabetic, uncomplicated hypertensive men. MAIN OUTCOME MEASURES: Triplicate overnight urine albumin determination and homeostasis model assessment (HOMA) of insulin resistance as a surrogate measure of insulin sensitivity. Additional parameters were fasting and post-load circulating glucose and insulin, lipids, body mass index, blood pressure and echocardiographic left ventricular mass. RESULTS: HOMA, fasting and post-challenge glucose and insulin, percentages of glucose-intolerant patients, triglycerides and high-density lipoprotein cholesterol levels did not differ across ascending urine albumin quartiles. Body mass index, blood pressure and ventricular mass were significantly greater in the upper quartiles, and the prevalence of obesity fivefold more frequent in the top as compared with the bottom urine albumin fourth. The statistical trend was unchanged after adjustment for HOMA, while accounting for systolic blood pressure and left ventricular mass by co-variance analysis abolished it. Eighty-eight patients bearing the phenotypic traits of the metabolic syndrome and a striking degree of insulin resistance and hyperinsulinemia showed urine albumin rates and prevalence of microalbuminuria comparable with the 183 patients who were not affected by that syndrome. CONCLUSIONS: Albuminuria is independent of insulin resistance and other phenotypic components of the metabolic syndrome in never-treated, non-diabetic essential hypertensive men. Microalbuminuria is more frequent in obese hypertensives but this association is explained by higher blood pressure more than insulin resistance.

Association between high-normal albuminuria and risk factors for cardiovascular and renal disease in essential hypertensive men.

BACKGROUND: Microalbuminuria (overnight urinary albumin excretion [UAE] > 15 microg/min) is associated with cardiovascular risk factors and predicts morbid events in hypertensive subjects. However, albuminuria is not a dichotomous variable, and a relationship with cardiovascular risk factors may extend below that conventional threshold. METHODS: We studied 186 never-treated, glucose-tolerant, normalbuminuric (overnight UAE < or = 15 microg/min), essential hypertensive men with normal renal function (serum creatinine < 1.4 mg/dL). Study variables were 24-hour ambulatory blood pressure (BP), cardiac structure and geometry (by echocardiography), body weight, fasting insulin levels, insulin sensitivity (the Homeostasis Model Assessment index), and creatinine clearance (from overnight collections or through the Cockcroft formula) analyzed as a function of ascending urine albumin quartiles (cutoff values, 4.3, 6.3, and 9.4 microg/min; n = 47, 45, 47, and 47, respectively). RESULTS: As compared with the three bottom fourths, patients with high-normal albuminuria (albumin, 9.4 to 15 microg/min) had a greater 24-hour BP, greater relative wall thickness, more frequent concentric left ventricular hypertrophy, heavier body size, increased fasting insulin levels, reduced insulin sensitivity, and greater creatinine clearance. CONCLUSIONS: High-normal albuminuria in uncomplicated essential hypertensive men is associated with an adverse cardiovascular and metabolic risk profile. Furthermore, hyperfiltration in the presence of minimally increased albuminuria may underlie an augmented glomerular blood flow and hydraulic pressure conducive to glomerular hypertension and, eventually, renal insufficiency. Overall, these data confirm the appropriateness to shift downward the limits for diagnosing microalbuminuria in essential hypertension, as indicated from previous prospective studies.

Left ventricular hypertrophy and its regression in essential arterial hypertension. A tissue Doppler imaging study.

The mitral annulus velocities of Doppler transmitral flow and pulsed-wave tissue Doppler imaging (TDI) were sampled by echocardiography for the assessment of left ventricular (LV) diastolic function in 118 never-treated essential hypertensive patients with normal systolic function and compared with those of 59 normotensive healthy subjects matched for age and sex. A selected group (n = 26) of the hypertensive study population was observed after 1 year of pharmacologic antihypertensive treatment to determine the behavior of TDI parameters in relation to eventual regression of LV hypertrophy (LVH). We found that the TDI early myocardial diastolic wave (E(m)) was significantly lower both in concentric and eccentric LVH. In addition, TDI late myocardial diastolic wave (A(m)) was significantly higher in concentric remodeling and concentric and eccentric hypertrophy. The TDI E(m)/A(m) ratio was significantly lower in all geometric remodeling subgroups. The E/A ratio Doppler transmitral flow velocity measured showed that of the 118 patients, only 32 (25%) could really be discriminated from normal, whereas individual analysis for TDI E(m)/A(m) at the mitral annulus septal level showed that of 118 patients 108 (91%) could be discriminated from normal P < .001). The LV mass was significantly less after 1 year of treatment (LVH regression), and TDI parameters showed a trend toward normalization, in particular of TDI E(m)/A(m) at the annular septal level. Pulsed-wave TDI analysis could enable not only the early assessment of whether a patient is still in an adaptive or compensatory phase before transition to irreversible damage (pathologic phase) but also the detection of precocious LV global diastolic dysfunction. With regard to this, more extensive randomized studies are needed to evaluate the effect of different pharmacologic treatments (calcium antagonists, beta-blockers, angiotensin I and II inhibitors) on TDI parameters.

The role of quantitative myocardial contrast echocardiography in the study of coronary microcirculation in athlete's heart.

Quantitative myocardial contrast echocardiography was performed with harmonic power Doppler analysis using the background subtraction and Levovist (Schering AG, Berlin, Germany) as contrast agent in a triggered modality. Quantitative analysis of echocontrast was performed offline with PC software, obtaining the transit curves of microbubbles through the coronary capillary system. Coronary microcirculation in athletes showed a behavior substantially comparable with control participants, although at a higher level. Training determines a physiologic left ventricular hypertrophy that counterbalances the dilatation in the left ventricular chambers because of the higher blood volume in athletes compared with control participants. Angiogenesis and several functional adaptations (relaxation of small coronary arteries, increased production of nitric oxide by the coronary endothelium, or both), represent the potential mechanisms that allow an optimal distribution of oxygen and of substrates to the hypertrophied myocardium of the athletes.

Early impairment of myocardial blood flow reserve in men with essential hypertension: a quantitative myocardial contrast echocardiography study.

OBJECTIVE: Aims of this study were to: (1) demonstrate whether quantitative myocardial contrast echocardiography could detect an index of myocardial blood flow reserve through the analysis of refilling curves generated by microbubble transit into myocardium both at rest and after vasodilatation induced by dipyridamole; and (2) explore with this method myocardial microcirculatory function in two different models (ie, patients with essential hypertension and control subjects). METHODS: Two groups of strictly age-matched men were studied (case-control study): 12 patients who were adults (28.2 +/- 0.2 years) and asymptomatic with never-treated essential hypertension, a mild degree of left ventricular hypertrophy, and normal left ventricular function; and 12 control subjects. Quantitative myocardial contrast echocardiography was performed in all study participants. We used second-generation ultrasound microbubbles as echocardiography contrast agent. Real-time color-coded power modulation was performed with a phased-array system interfaced to a S3 transducer (1.3-3.6 MHz). RESULTS: In control subjects there was little increase in myocardial blood volume (30%) between basal and hyperemic status (P <.05); in patients with hypertension this parameter increased by 22% (P <.05). Myocardial blood velocity increased after dipyridamole by 270% in control subjects (P <.01), whereas for patients with hypertension this parameter increased only by 150% (P <.02). The index of myocardial blood flow reserve was significantly lower for patients with hypertension than in control subjects (3.3 +/- 0.3 vs 4.4 +/- 0.3, respectively; P <.01). CONCLUSION: Results of our study documented that myocardial microcirculation in young adult patients with hypertension showed an early impairment in the vasodilatation capacity of the resistance arterioles under dipyridamole-induced hyperemia, as demonstrated by a reduction of myocardial blood flow reserve. Myocardial blood velocity increased after dipyridamole induction in control subjects, whereas patients with hypertension showed a significantly lesser increase. Myocardial blood flow reserve was significantly lower for patients with hypertension because of an early impairment in vasodilatation capacity of resistance arterioles under dipyridamole-induced hyperemia.

Ultrasonic tissue characterization and Doppler tissue imaging in the analysis of left ventricular function in essential arterial hypertension: a preliminary study.

It is not known if diastolic abnormalities are independent of systolic dysfunction in arterial hypertension. We studied three groups of 10 male subjects of comparable mean age (31.6 +/- 3.5 years), weight, and height: Athletes (A) (cyclists), essential hypertensive patients (H), and controls (C). Ultrasonic myocardial integrated backscatter signals (IBS) of the septum and the posterior wall were analyzed, while the systo-diastolic variation of the backscatter was considered as a cyclic variation index (CVI(ibs)). Myocardial velocities across the left ventricular major axis were sampled at septum and lateral wall levels by pulsed-wave Doppler tissue imaging (DTI). CVI(ibs) at the septum and the posterior wall were significantly lower in the hypertensive group in comparison with athletes and controls, who were comparable. Early diastolic myocardial velocity (E(m)) of the lateral wall and of the septum were significantly lower in hypertensives, while the late diastolic myocardial velocity (A(m)) was significantly higher in hypertensives in comparison with athletes. The E(m)/A(m) at the septum level was significantly lower in hypertensives in comparison with athletes and controls. Significant correlations were found between CVI and DTI parameters: CVI(ibs) and E(m)/A(m) septum (r = 0.50, P < 0.002). Furthermore, significant correlations were found between mean arterial pressure (MAP) and E(m)/A(m) septum (r = - 0.65, P < 0.001). Ultrasonic tissue characterization with the intrinsic contractility study and the evaluation of the regional diastolic function should, therefore, represent a new integrated diagnostic modality for the evaluation of left ventricular hypertrophied intramyocardial function. This study demonstrated that diastolic abnormalities of left ventricular function, in arterial hypertension, are related and progress with systolic intrinsic dysfunction.

Assessment of myocardial perfusion with intravenous contrast echocardiography: comparison with (99) Tc-tetrofosmin single photon emission computed tomography and dobutamine echocardiography.

The aim of the study was to evaluate the accuracy of intermittent, harmonic power Doppler (HPD) during intravenous Levovist infusion in identifying myocardial perfusion abnormalities in patients with recent infarction. Fifty-five patients with first acute myocardial infarction, successfully treated by primary PTCA, were studied after 1 month by myocardial contrast echocardiography (MCE), 99mTc tetrofosmin single photon emission computed tomography (SPECT), and low dose dobutamine echocardiography (DE). Scoring myocardial perfusion as normal, moderately, or severely reduced; MCE and SPECT were in agreement in 71% of segments(k = 0.414). Discordance was mainly due to ventricular walls with normal enhancement by MCE and moderate perfusion abnormalities by SPECT. Scoring perfusion as present or absent, the agreement significantly improved up to 86% (k = 0.59). Sensitivity and specificity of HPD for identifying SPECT perfusion defects were 63% and 93%, respectively. The agreement between MCE and SPECT was higher(85%, k = 0.627)in patients with anterior infarction. An improvement in regional contractile function was noted after dobutamine in 79 dysfunctional segments. A normal perfusion or a moderate perfusion defect by MCE were detected in 71 of 79 of these segments, while a severe perfusion defect was observed in 59 of 85 ventricular segments without dobutamine-induced wall-motion improvement. Sensitivity and specificity by HPD in detecting segments with contractile reserve were 90% and 69%, respectively. Thus, intermittent HPD during Levovist infusion allows myocardial perfusion abnormalities to be detected in patients with recent infarction. This method has a limited sensitivity but a high specificity in detecting SPECT perfusion defects, and a good sensitivity but a limited specificity in detecting contractile reserve.

Excess aldosterone is associated with alterations of myocardial texture in primary aldosteronism.

Hyperaldosteronism has been causally linked to myocardial interstitial fibrosis experimentally, but it remains unclear if this link also applies to humans. Thus, we investigated the effects of excess aldosterone due to primary aldosteronism (PA) on collagen deposition in the heart. We used echocardiography to estimate left ventricular (LV) wall thickness and dimensions and for videodensitometric analysis of myocardial texture in 17 consecutive patients with PA and 10 patients with primary (essential) hypertension who were matched for demographics, casual blood pressure, and known duration of hypertension. The groups differed in serum K+, ECG PQ interval duration, plasma renin activity, and aldosterone levels (all P< or =0.002) but not for casual blood pressure values, demographics, and duration of hypertension. Compared with hypertensive patients, PA patients showed a higher LV mass index (53.7+/-1.8 versus 45.5+/-2.0 g/m(2.7); P=0.008) and lower values of the cyclic variation index of the myocardial mean gray level of septum (CVI(s); -12.02+/-5.84% versus 6.06+/-3.08%; P=0.012) and posterior wall (-11.13+/-6.42% versus 8.63+/-9.62%; P=0.012). A regression analysis showed that CVI(s) was predicted by the PQ duration, supine plasma renin activity, plasma aldosterone, and age, which collectively accounted for approximately 36% of CVI(s) variance. PA is associated with alterations of myocardial textures that suggest increased collagen deposition and that can explain both the dependence of LV diastolic filling from presystole and the prolongation of the PQ interval.